An unknown solution turns red litmus blue and turmeric reddish brown. What is the nature of the solution?

Correct answer: Basic

Indicators reveal the nature of a solution through characteristic colour changes. A basic solution turns red litmus blue because it provides an alkaline medium. It also changes yellow turmeric to reddish brown, which is another common test for a base. An acid would turn blue litmus red, while a neutral solution normally causes neither stated change. Therefore the two observations consistently support option B, basic.