There are certain spheres of one's life in which one should go by one's own (171) _______ rather than follow another's counsel. The choice (172) ______ one's subject of study is one such sphere. (173) _____ one is genuinely interested in a subject, one (174) ______ never opt for it. India is already full of (175) _____ pegs in round holes, who are unfit for their roles and are doing more harm than good.

Options

A. ought
B. would
C. could
D. should

Answer

D

Explanation

(d) should.
The word “Should” expresses the meaning of obligation.
It generally states that if the person is not interested in the subject they must or should not opt for it.
Other modal auxiliary options don.t fit to the context.