13. The expression $\frac{2 a^{6} b^{2} c}{10 a^{2} b^{-2} c}$ written in simplest form is a. $\quad 5 a^{4} b^{4}$ b. $\quad \frac{a^{4}}{5}$ c. $\frac{a^{4} b^{4}}{5}$ d. $\quad 5 a^{8} b^{0} c^{2}$

Step 1 ：Simplify the expression: \(\frac{2 a^{6} b^{2} c}{10 a^{2} b^{-2} c}\)

Step 2 ：Combine like terms: \(\frac{2 a^{6-2} b^{2-(-2)}}{10}\)

Step 3 ：Simplify the exponents: \(\frac{2 a^{4} b^{4}}{10}\)

Step 4 ：Divide the coefficients: \(\frac{a^{4} b^{4}}{5}\)

Step 5 ：Final Answer: \(\boxed{\frac{a^{4} b^{4}}{5}}\)