waste, v. squander, misuse, throw away

waste, adj. unwanted, spare, remaining, surplus, excess
waste, n. litter, garbage, trash, rubbish

Which word would best replace waste in the sentence below?

They made sure not to waste their time doing anything but the job, so they would have plenty of time to relax later.
A.
excess
B.
misuse
C.
spare
D.
rubbish