Soumita Ghosh wrote:


can anyone explain me how can be "had received" when there is no simple past tense in the sentence?
I did not choose A for that reason.

As per my knowledge when we will use "had" in the sentence there must be one simple past tense in the sentence. As per my understanding to enrolling is not in simple past tense.

"A" is the best of the choices here, not perfect, but the best. If there was an option that simply said "received graduate degrees in scientific fields prior to enrolling" that would be best.

Here's a piece of guidance I like for past perfect -- "The Past Perfect expresses the idea that something occurred before another action in the past. It can also show that something happened before a specific time in the past."

The problem with "E" is 'prior to when they were enrolling', which is fraught with tense confusion and incorrect idiomatic usage.

Hope this helps.

-Brian