Correct Answer: D

Your Answer:

Explanation

D

This is a Vocabulary question, as it's asking for a logical and precise word or phrase for the blank. Read the text and highlight what can help fill in the blank. The text describes Whitsett's ground-breaking development and states that astronautics owes much to him. A good word for the annotation box based off this information would be "innovative."

• (A) and (B) are wrong because dubious (doubtful) and futile (hopeless) are the Opposite tone of "innovative."

• (C) is wrong because galvanizing, which means "stimulating," doesn't match "innovative."

• (D) is correct because avant-garde means "pioneering," which matches "innovative."