If turmeric turns reddish-brown and phenolphthalein turns pink in a solution, what is the nature of the solution?

Correct answer: Basic

The governing concept is the colour response of acid–base indicators. Turmeric changes to reddish-brown in a basic medium, and phenolphthalein is colourless in acidic or neutral conditions but turns pink in a basic solution. Since both independent observations indicate alkalinity, option B is correct. An acidic solution would not produce this pair of changes, neutrality would keep phenolphthalein colourless, and “gaseous” describes a state of matter rather than the chemical nature shown by the indicators.