I see the correct answer to the third question is b/c the modifier correctly refers to the trade deficit.

The first screenshot I feel is just an overall horrible sentence. I guess the correct answer is truly the least worst sentence.

For the middle question, in the answer I chose, the "they" is vague, however I thought the sentence required the verb were, so I chose this answer.

First of all, please post ur questions or screen shots without mentioning the OA, or in the screen shots before checking the answer.

In this A/B/C are wrong...because "When.." is used to refer to time or time periods....

D is wrong because in D, "it" is used for referring to gas in first part of sentence, and "gas" is used in second part...
Therefore, pronoun and paralleism error...

E stands best