Studies have shown that regularly used household washing machines are ...
Studies have shown that regularly used household washing machines are teeming with bacteria that find their way onto our clothes and consequently onto us, causing various bacterial infections. Rinsing these machines with bleach is an effective way to get rid of such bacteria. However certain other studies have shown that bleach when used in the undiluted form can severely corrode the metal drum in the machines. Thus, bleach, as long as it is diluted properly, is an effective and safe means of eliminating any health risks from such washing machines.
The argument above will not hold unless which of the following statements holds true?
Argument Analysis
Pre-Thinking
Conclusion Clarification
The author concludes that bleach, as long as it is diluted properly, is an effective and safe means of eliminating any health risks from regularly used HWMs, which are a source of bacterial infections,since bleach, when used in the undiluted form, can severely corrode the metal drum in the machines.
Pre-Thinking Approach
To pre-think assumptions, let’s see how we can falsify this conclusion. To do so, we will look at the logical structure, focusing on linkage 1 and 2 and the conclusion. We will understand the condition under which the conclusion is falsified. The assumption then will be that the condition does not exist.
Linkage#1 – Rinsing these machines with bleach is an effective way to get rid of such bacteria (bacteria that cause bacterial infection).
- Falsification Condition: What if such washing machines may pose a health risk other than bacterial infection, i.e. any infection other than bacterial infection? In such a case, bleach may not be effective against other health risks.
- Assumption: Besides bacteria, there are no other disease causing organisms that are found in regularly used HWMs.
Linkage#2 – Certain other studies have shown that bleach, when used in the undiluted form, can severely corrode the metal drum in the machines.
- Falsification Condition: What if bleach in diluted form reacts with some other component of the machine and releases harmful chemicals? In such cases, the diluted bleach cannot be considered an effective and safe means to eliminate any health risks.
- Assumption: The use of diluted bleach in HWMs does not lead to the release of any harmful chemicals that can find their way to humans.
With this understanding in mind, let’s take a look at the option statements.
Answer Choices
A
The process of diluting bleach with water by a person cannot have harmful effects on the body of that person.
Incorrect - Irrelevant
The information given in this choice, which relates to how the bleach is diluted and the effect of the same before it’s used in the mentioned washing machines, is irrelevant.
B
Diluted bleach is as effective as concentrated bleach in elimination of bacteria from the washing machines.
Incorrect - Irrelevant
Although we cannot take it for granted that concentrated bleach means the same as regular bleach, even if we did so, this choice does not give us any concrete information. On negating this statement, we get that diluted bleach is not as effective as concentrated bleach. This could mean that it is either more or less effective than concentrated bleach. Since the negation of the statement does not shatter the conclusion, it is not an assumption.
C
Corrosion of the metal drum in the washing machines is the only negative impact of the use of concentrated bleach in washing machines.
Incorrect - Irrelevant
The conclusion talks about the effects of diluted bleach whereas this option statement is about the effects of concentrated bleach. Clearly, this option is irrelevant.
D
Diluted bleach does not leave any harmful residues in the washing machine that attach themselves to our clothes.
Correct
This option is written along the lines of our pre-thought assumption identified for linkage 2. If diluted bleach does leave any harmful residue, which attaches itself to clothes, then that can be considered a health risk and thus diluted bleach can’t be considered effective for eliminating all health risks.
E
Rinsing the household washing-machines with bleach is one of the most cost effective methods of eliminating bacteria from these machines.
Incorrect - Irrelevant
This option concerns itself with cost, which is irrelevant to the argument at hand.