Sentence 2 has the correct parallel structure.
D) Did you read the long, interesting essay Betty wrote?
It's a nonessential word, clause, or sentence added to an already grammatically complete sentence. It's most commonly set off by brackets, but it can also be set off by commas or dashes.
Example:
My mother went to the supermarket and picked up some strawberries (my favorite fruit) earlier today.
It would seem to be C because he choose that field and since it’s unionized he is having a hard time finding a open spot
Answer:
According to Randy, Bob wanted to be given a set of limits that he had to obey.