Hi 750+,
Brent has provided a great explanation that TESTS VALUES, so I won't rehash that here.
Instead, I'm going to point out the Number Properties that this question is based on. These are "math rules" that are worth knowing, as Number Properties show up on a variety of questions in the Quant section:
1) ANY positive or negative number, when raised to an EVEN INTEGER power, becomes positive.
2) 0, raised to ANY power, is still 0.
3) Positive fractions, when raised to a POSITIVE power GREATER THAN 1, become SMALLER
Number Properties tend to show up in Roman Numeral questions and in DS questions, so keep an eye out for them (and learn them) during your studies.
GMAT assassins aren't born, they're made,
Rich