Choose most appropriate option to fill in the blank:
Mr Clark ________ (work) in a bank for 15 years. Then he gave it up.

Solution (By Examveda Team)

strong>Past Perfect Tense is used to express an action that was completed before another past action. In this case, Mr. Clark worked in a bank for 15 years and then gave it up. To show that his working period in the bank was completed before he gave it up, the past perfect tense is appropriate.
Option B: had worked correctly indicates that the action of working in the bank was completed before another past event (giving it up).
Options A, C, and D do not convey this sequence of events correctly.