Methyl orange turns yellow and phenolphthalein turns pink in a solution. What is the nature of the solution?

Correct answer: Basic

Indicator colour ranges provide the governing evidence. Methyl orange is yellow in a neutral or alkaline medium and red in a sufficiently acidic medium. Phenolphthalein is pink in an alkaline medium and colourless in acidic or near-neutral conditions. Seeing both yellow methyl orange and pink phenolphthalein therefore indicates that the solution is basic, sufficiently above the phenolphthalein transition range. An acidic solution would make methyl orange red and phenolphthalein colourless. Hence option A is correct.