Choose the correct simplification of the expression (a^4/b^2)^3 a: a^7/b^5 b: a^12/b^6 c: ab^9 d: a^12b^6

The answer is B:  a^12/b^6

Proof:

Simplify the following:
(a^4/b^2)^3

Multiply each exponent in a^4/b^2 by 3:
(a^(3×4))/((b^2)^3)

3×4 = 12:
a^12/(b^2)^3

Multiply exponents. (b^2)^3 = b^(2×3):
a^12/b^(2×3)
2×3 = 6:
  a^12/b^6