The hospitalization was prolonged because of the absence of any good choices for oral medications to treat his UTI.

1.This is a run-on that requires a comma before the word because.
2. This is a run-on that requires a semicolon before the word because.
3. This is a fragment that can be fixed by adding a verb after hopitalization.
4. This is a fragment that requires a subject.
5. The sentence is fine as it is.
Answer:
NOT # 3 & #4
I don't think it is two or more sentences.
MY Answer is #5.

I agree. :-)

Your answer is correct. The sentence is fine as it is. It is a complete sentence that does not require any additional punctuation or changes. The sentence effectively conveys the intended message about the prolonged hospitalization due to the absence of suitable oral medications for treating the urinary tract infection (UTI).