What colour does methyl orange become in a basic solution?

Correct answer: Yellow

The governing concept is the colour change of an acid-base indicator. Methyl orange is red in an acidic medium and yellow in a neutral or basic medium. Therefore, when it is added to a basic solution, the observed colour is yellow. Pink and black are not the characteristic methyl-orange colours, and red indicates an acidic rather than a basic condition. Thus option B is the only correct answer.