It is very important question...
and very jumbled also...
remember always that, acid turns blue litmus into red...
And base turns red litmus into blue ....
trick1:-- Acid(B-R) & Base(R-B)....
trick2:--Acid(Sour in taste,ex.turmuric,Orange)
trick3:--Base(bitter in taste,ex.NaOH...
we can commonly find that...base contain OH)...

**Acid Turns Blue Litmus Red**

**Explanation:**
Acids are a group of substances that have certain characteristics and properties. One of the most common properties of acids is their ability to change the color of litmus paper. Litmus paper is a type of indicator paper that is used to determine whether a solution is acidic or basic.

When an acid is added to blue litmus paper, it turns the paper red. This is because blue litmus paper is specifically designed to change color in the presence of an acid. The blue color of the litmus paper is due to the presence of a pigment called litmus. Litmus is extracted from lichens and has the ability to change its color depending on the pH of the solution it is in contact with.

Acids are substances that release hydrogen ions (H+) when dissolved in water. These hydrogen ions react with the litmus pigment in the blue litmus paper, causing it to change its structure and, consequently, its color. The litmus pigment undergoes a chemical reaction with the hydrogen ions, resulting in a shift from its blue form to its red form. This change in color is a clear indication that an acid is present.

It is important to note that not all substances can turn blue litmus paper red. Only acidic substances have this ability. Basic substances, on the other hand, have the opposite effect on litmus paper. They turn red litmus paper blue. This is because basic substances release hydroxide ions (OH-) when dissolved in water, which react with the litmus pigment in the red litmus paper, causing it to change its color.

In conclusion, the correct answer is option A, which states that acids turn blue litmus paper red. This is due to the chemical reaction between the hydrogen ions released by acids and the litmus pigment in the blue litmus paper, resulting in a change in color from blue to red.