Which one of the following sentences is correct?

A Why have you done this?

B Why you have done this?

C Why did you have done this?

D Why you had done this?

Correct Answer: Option A

সাধারণ নিয়ম নিম্নরূপ: WH word + have/has + Subject + মূল্য verb এর past participle + extension

সঠিক বাক্য- Why have you done this?