Answer:
The answers are A: In the end, neither side gained territory; B: Neither side was able to reunify the peninsula; E: The war ended, but the countries did not sign a peace agreement.
Step-by-step explanation:
From 1951-1953, the war was a stalemate. Neither sides had gained any territory. Neither of them also didn't win any major battles. Both sides were miserable, so the United Nations, North Korea, and China agreed to sign a armistice agreement. (Also note that they signed an armistice agreement, not a peace agreement, so E. would be one of the correct answers.)
I also got it correct on my quiz.