To find an expression equivalent to \( \frac{1}{8^5} \), we can use the property of exponents that states:
\[ \frac{1}{a^n} = a^{-n} \]
Applying this property to \( \frac{1}{8^5} \), we get:
\[ \frac{1}{8^5} = 8^{-5} \]
Thus, the correct response from the options provided is:
8^−5