To simplify the expression \( r^{-4} p^{-8} \), we can make use of the properties of exponents. The expression can be rewritten as:
\[ \frac{1}{r^4} \cdot \frac{1}{p^8} = \frac{1}{r^4 p^8} \]
Thus, the correct response is:
1 \( r^4 p^8 \)
This means the simplified form is the fraction with numerator 1 and denominator \( r^4 p^8 \).