Methyl orange turns red in an acidic solution. If enough base is added to the same solution, in which direction will the color change?

Correct answer: Red to yellow

Methyl orange is red in an acidic medium and yellow in a neutral or alkaline medium. Adding enough base consumes hydrogen ions through neutralisation, so the pH rises and the solution moves from the acidic indicator range toward the alkaline range. Consequently, the observed colour changes from red toward yellow. The other choices describe the reverse change or colours that do not match methyl orange in this situation.