Answer: second option. (NOTE: If the first option is
, then it would be an equivalent expression too, because:
)
Explanation:
To solve this problem you must keep on mind the following exponents rule:

Therfore, you have that:

This means that the number -2 must be multiply by itself three times. Therefore, you obtain the folllowing result:

If the first option is
, then it would be an equivalent expression too, because:
