After working for two hours, the essay started to take shape, and he

1. Eliminate A and E because they both say, in different ways, that the essay was working for two hours. The subject of WORKING is in both cases ESSAY, so the meaning is nonsensical.

2. Reserve B.

3. Eliminate C because HE BEGUN is grammatically incorrect: the Past Simple is the tense required here, and its form in this verb is BEGAN.

4. Eliminate D because it remains unclear who or what was working on it for two hours. Compare this phrase with the clause in option B: after he had worked on it for two hours. In B it is clear who was working. Furthermore, the change to the Past Perfect is required here: first the student worked and then he began, so the correct sequence is HAD WORKED ... HE BEGAN.

5. B is therefore the correct answer.

If you like this post, please give it KUDOS.

You can also visit us at https://www.xgmat.com/