Add or Subtract $-8 m^{2} \sqrt[4]{7 m^{3}}-4 m^{2} \sqrt[4]{7 m^{3}}$ A) $12 m^{2} \sqrt[4]{7 m^{3}}$

Multiple Choice

Add or subtract. Assume all variables represent nonnegative real numbers.

- $-8 m^{2} \sqrt[4]{7 m^{3}}-4 m^{2} \sqrt[4]{7 m^{3}}$

A) $12 m^{2} \sqrt[4]{7 m^{3}}$
B) $-12 m^{2} \sqrt[4]{7 m^{3}}$
C) $-12 m^{3} \sqrt[4]{7 m}$
D) Cannot simplify