A student factors $a^6-64$ to $\left(a^2-4\right)\left(a^4+4 a^2+16\right)$.
Which statement about $\left(a^2-4\right)\left(a^4+4 a^2+16\right)$ is correct?
AThe expression is equivalent and is completely factored.
BThe expression is equivalent, but the $\left(a^2-4\right)$ term is not completely factored.
CThe expression is equivalent, but the $\left(a^4+4 a^2+16\right)$ term is not completely factored.
DThe expression is not equivalent.
Which statement about $\left(a^2-4\right)\left(a^4+4 a^2+16\right)$ is correct?
AThe expression is equivalent and is completely factored.
BThe expression is equivalent, but the $\left(a^2-4\right)$ term is not completely factored.
CThe expression is equivalent, but the $\left(a^4+4 a^2+16\right)$ term is not completely factored.
DThe expression is not equivalent.