Incorrect. Rewrite using a rational exponent: $\displaystyle{{\left({4}{{a}}^{{2}}{{b}}^{{40}}{{c}}^{{2}}\right)}}^{{\frac{{1}}{{4}}}}\usepackage{cmbright}\Huge\$

Use the laws of exponents to simplify the expression. Factor 4 and simplify again. Change any factors with exponent $\displaystyle\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ back to radical form. The correct answer is 2ac.