What is the simplified form of 3a^4b^-2c^3

A. 3a^4c^4/b^2
B. 3a^4/b^2c^3
C. 81a^4/b^2c^3
D. 81a^4c^3/b^2

The simplified form of 3a^4b^-2c^3 is B. 3a^4/b^2c^3