Answer is: b) blue.
Neutral litmus paper turns red in acidic solutions and turns blue in alkaline solutions. At neutral pH, litmus paper does not change color.
Acids and bases have opposite properties and have the ability to neutralize each other. Acids taste sour, give sharp stinging pain in a wound and react with metals to produce hydrogen gas.
Bases turn red litmus paper blue and acids turn blue litmus paper red.
