**Answer:**

The correct answer is option 'B' - Bacteria.

**Explanation:**

Bacteria are single-celled microorganisms that are found almost everywhere, including in water. Some bacteria can be harmful to humans and cause various diseases. Two of the diseases caused by harmful bacteria in water are typhoid and jaundice.

1. **Typhoid**: Typhoid fever is a bacterial infection caused by the bacterium Salmonella typhi. This bacterium is commonly found in contaminated water and food. When a person consumes water or food contaminated with the bacteria, they can develop symptoms such as high fever, headache, stomach pain, and diarrhea. Typhoid fever can be a serious illness and requires medical treatment.

2. **Jaundice**: Jaundice is a condition characterized by yellowing of the skin and eyes. It is caused by an increase in bilirubin, a yellow pigment produced when red blood cells break down. One of the causes of jaundice is infection with the bacteria called Leptospira. This bacterium is commonly found in water contaminated with animal urine. When a person comes into contact with contaminated water, the bacteria can enter their body and cause an infection. Symptoms of leptospirosis, the disease caused by Leptospira, include fever, headache, muscle pain, and yellowing of the skin and eyes.

In both cases, the harmful bacteria are present in water and can cause infections when consumed or when there is contact with contaminated water. It is important to ensure that water sources are clean and free from harmful bacteria to prevent these diseases. Water treatment methods, such as filtration, chlorination, and boiling, can help eliminate or reduce the presence of harmful bacteria in water, making it safe for consumption.

Therefore, the harmful microbe in water that causes typhoid and jaundice is bacteria (option B).

Every water bone disease ( caused by water impurities) is caused by Bacteria in water.. Hence typhoid and jaundice are water bone diseases they are caused by Bacteria.