8. There are $n$ integers, whose product is $n$, and whose sum is zero. Then $n$ ( ).
(A) must be even
(B) must be odd
(C) may be even or may be odd
(D) does not exist

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8. (A).
$1, 2, -1, -2$ satisfy the condition, that is, $n$ can be 4.
If $n$ is odd, then $n$ numbers are all odd, the sum of an odd number of odd numbers cannot be zero.