Concept:Litmus is a natural indicator that shows different colours in acidic, basic, and neutral media.
Explanation:Litmus is a purple dye extracted from lichens.
In a neutral medium, litmus retains its original colour, which is purple.
If the medium is acidic, litmus turns red.
If the medium is basic or alkaline, litmus turns blue.
Therefore, neutral litmus solution or paper appears purple.
Answer:A. purple