To answer this question, you need to have knowledge about the music director of the movie "3 Idiots".
Option A) A.R. Rahman - This option is incorrect because A.R. Rahman did not compose the music for "3 Idiots".
Option B) Pritam - This option is incorrect because Pritam did not compose the music for "3 Idiots".
Option C) Santanu Moitro - This option is correct because Santanu Moitro composed the music for "3 Idiots".
Option D) Shankar-Ehsan-Loy - This option is incorrect because Shankar-Ehsan-Loy did not compose the music for "3 Idiots".
The correct answer is Option C) Santanu Moitro. This option is correct because Santanu Moitro is the music director of "3 Idiots".