The Emperor Napolean got by on four hours of sleep a night, and the scientist Thomas Edison claimed it was ________ waste of time.

• A. a
• B. the
• C. some
• D. such

Answer: (A)

Choosing the indefinite article before a singular, countable noun is the key. The phrase “a waste of time” is how we generalize something as a poor use of time, referring to one instance without naming it specifically. Here, we’re not pointing to a particular waste that both speaker and listener know, so the indefinite article is appropriate. Using “the” would imply a specific waste of time already identified; “some” sounds odd with this fixed expression in a general statement; and “such” needs the form “such a” to be natural. So the natural completion is “it was a waste of time.”