Pick out the most effective word(s) from the given words to fill in the blank to make the sentence meaningfully complete.
The Hubble Space Telescope will search for planets around the stars, a key to the ...... for extraterrestrial life, and examine interstellar dust and gases out of which stars are born.
A.
perception
B.
discovery
C.
enquiry
D.
quest
Correct answer is D
No explanation has been provided for this answer.
