One of your answers is correct.
A classic teacher response now is to point out that if I were simply to tell you the answer, you'd learn nothing. If you had to research it for yourself, you're much more likely to understand and remember.
It didn't take me long to google the answer, time I didn't mind wasting as I was interested in the answer. I don't want to just do your homework for you.
Your Q perhaps should have mentioned that it forms a diacid.