Which of the following sentence is in the past perfect continuous tense:

Explanation

The sentence "Had Sam and John been cheating on the exams before the school put monitors in the classroom?" is in the past perfect continuous tense. It is used to describe an ongoing action or situation in the past that occurred before another specific past event.In this case, the sentence suggests that Sam and John were continuously cheating on exams before the school implemented monitors in the classroom. The use of "had been cheating" indicates the ongoing nature of their cheating activities prior to the implementation of monitors.The sentence implies that the action of cheating had been happening for some time before the school took action.