In a solution red litmus turns blue and turmeric becomes reddish-brown. What is the nature of the solution?

Correct answer: Basic

The governing concept is the characteristic response of acid–base indicators. A basic solution changes red litmus to blue, and turmeric develops a reddish-brown colour in the presence of a base. Since both independent observations point to alkalinity, option B is correct. An acid would produce the opposite litmus change, neutrality would not give these characteristic responses, and “gaseous” describes a state rather than the solution’s chemical nature.