Answer:
The sentence that draws attention equally to both clauses is:
D. We did not sleep well last night; thunderstorms kept waking us.
Explanation:
The first three options all consist of a main clause and a dependent clause. That establishes a relationship of subordination. In that sense, one clause seems to be more important that the other, since the subordinate one depends on the main clause for it to have a complete meaning.
However, the last option does not create such a relationship. What "unites" the clauses is merely punctuation. Both clauses remain as independent. That means they both express complete thoughts on their own. When read out loud, unlike the other options, they have similar intonations, which also helps us notice they are equally important. Therefore, we can say the last option draws attention equally to both clauses.
