The expression that is correctly developed to use the Power Rule of Exponents is:
\((7^4)^8\)
When applying the Power Rule of Exponents, which states that \((a^m)^n = a^{m \cdot n}\), this expression can be simplified further:
\((7^4)^8 = 7^{4 \cdot 8} = 7^{32}\)
If you have other expressions in mind or need further clarification, please let me know!