I accept your plan.

Answer: Option C

Accept : consent to receive or undertake (something offered).
Deny : state that one refuses to admit the truth or existence of.
Dismiss : order or allow to leave; send away.
Reject : dismiss as inadequate, unacceptable, or faulty.
Decline : (typically of something regarded as good) become smaller, fewer, or less; decrease.

Antonym of Accept is Reject