What is ${\left( 7^{4} \right)^{-4}}$

${7^{ -16 }}$ ${\frac{1}{2401}^{ 0 }}$ ${\frac{1}{2401}^{ \frac{1}{256} }}$ ${7^{ \frac{1}{256} }}$ ${7^{ 0 }}$ ${\frac{1}{2401}^{ -16 }}$