Which expression is a perfect cube?

A monomial is a perfect cube when its numerical coefficient is a perfect cube and every variable’s exponent is a multiple of 3. In choice B, 64 = 4³, and both 27 and 125 are multiples of 3, so 64x²⁷y¹²⁵ is a perfect cube. The other choices either have a coefficient that is not a perfect cube or an exponent that is not divisible by 3.

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