The Principal hardly managed to give the papers a cursory glance.

Answer: Option C

Cursory : hasty and therefore not thorough or detailed.
Superficial : existing or occurring at or on the surface.
Through : moving in one side and out of the other side of (an opening, channel, or location).
Thorough : complete with regard to every detail; not superficial or partial.
Curious : eager to know or learn something.

Antonym of Cursory is Thorough