The officer asked the clerk to expedite the matter.

Answer: Option D

expedite : make (an action or process) happen sooner or be accomplished more quickly.
postpone : cause or arrange for (something) to take place at a time later than that first scheduled.
defer : put off (an action or event) to a later time.
adjourn : break off (a meeting, legal case, or game) with the intention of resuming it later.
delay : make (someone or something) late or slow.


Antonym of expedite is delay