Question

technical terms
the power plant of a submarine is designed to be extremely efficient, so the submarine can stay underwater for long periods of time.
efficient means \achieving maximum productivity with minimum wasted effort or expense.\
which of the following words would be considered an antonym for efficient?
wasteful
accomplished
experienced
proficient

Explanation:

Efficient means achieving maximum productivity with minimum waste. Wasteful means using resources carelessly and without purpose, which is the opposite. The other words - accomplished, experienced, proficient - do not convey the opposite meaning of efficiency.

Answer:

A. wasteful