Answer
$\huge\color{blue}{m^6}$
Work Step by Step
$\large (m^2)^3 \ne m^5$
Lets see where the mistake is.
This would make sense if we were multiplying two numbers with the same base. We would want to add the $\color{red}{exponents}$ together.
$\large (m^\color{red}{2})(m^\color{red}{3}) = m^{\color{red}{(2+3)}} = m^\color{red}{5}$
But here, we are raising a $\color{green}{base}$ to an $\color{red}{exponent}$ so we need to multiply.
$\large \color{green}{(m^2)}^\color{red}{3} = m^{( \color{green}{2}*\color{red}{3})} = m^6$
The correct answer is:
$\huge\color{blue}{m^6}$
