Question

Then they ___(8)___ (fire) at by the militants. Thereafter, the militants forcibly entered a house and changed their clothes before escaping.

• A. were fired
• B. have been fired
• C. had been fired
• D. was fired

Answer 1

The correct option is A were fired

Here, 'were fired' in simple past tense is correct because it is used to indicate an action already completed. Here, the personnel 'were fired' (past action) at by the militants.
'Have been fired' in present perfect continuous is incorrect because it is used to indicate an action which started at some point in the past and may or may not be complete.
'Had been fired' in past perfect continuous tense is incorrect because it is used to indicate an action in the past that began before a certain point in the past and continued up untill that time.
'Was fired' is incorrect as there is 'they' (plural) in the beginning of sentence. So, 'were' is correct.