He gave an expeditious reply.

Answer: Option D

Exact : not approximated in any way; precise.
Slow : moving or operating, or designed to do so, only at a low speed; not quick or fast.
Elaborate : involving many carefully arranged parts or details; detailed and complicated in design and planning.
Prompt : done without delay; immediate.
Expeditious : done with speed and efficiency.

Synonym of Expeditious is Prompt