ANS:A - orange yellow in alkaline medium.

Methyl orange indicator actually turns yellow in alkaline (basic) medium, not orange-yellow. In an alkaline medium, methyl orange undergoes deprotonation, resulting in a color change from its acidic form (orange) to its basic form (yellow). This color change occurs because the indicator molecule gains a negative charge when it loses a proton in the basic environment. As a result, the color of the solution shifts to yellow, indicating the presence of a base. Therefore, the correct statement is: Methyl orange indicator turns yellow in alkaline (basic) medium. Thank you for bringing this to my attention, and I apologize for any confusion.