What is the value of the integer n?

i) n(n+2)=15

ii) (n+2)^n=125

The given answer is C (both together are sufficient).

According to my understanding:

From (i), n may be 3 or -5.

From (ii), n is 3.

So I think (ii) is sufficient while (i) not.

Is there any other possibilities for n from (ii)?

Thanks a lot!

谢谢,觉得天山的题目里有一些都拿的不是很准..

有这个感觉,所以要多上来讨论,要是还是不确定,那就相信自己的理解.