Is the following sentence punctuated correctly, and why?

I spent the night in the hospital and couldn't get home in time, therefore, I was not able to finish my paper on time.

A. No, because the adverbial conjunction therefore requires two semicolons around it to indicate that it is changing the subject of the sentence.

B. No, because this sentence is a run-on and needs to be separated into two distinct sentences to remove the problem.

C. No, because the adverbial conjunction therefore is combining the two clauses, and when it separates two independent clauses, a semicolon is required before the adverbial conjunction.

D. Yes, because the adverbial conjunction therefore is combining the two ideas, and commas are required to go around adverbial conjunctions.