Answer :

Let's work through the given expression step-by-step to find its equivalent form.

We start with the expression:
[tex]\[ \left(a^{-2} \cdot 8^7\right)^2 \][/tex]

First, apply the power rule [tex]\((x^m)^n = x^{mn}\)[/tex] to each term inside the parentheses:
[tex]\[ (a^{-2})^2 \cdot (8^7)^2 \][/tex]

Now, simplify each term separately:
[tex]\[ (a^{-2})^2 = a^{-4} \][/tex]
[tex]\[ (8^7)^2 = 8^{7 \cdot 2} = 8^{14} \][/tex]

Combining these results, the expression simplifies to:
[tex]\[ a^{-4} \cdot 8^{14} \][/tex]

Therefore, the equivalent expression is:
[tex]\[ \boxed{a^{-4} \cdot 8^{14}} \][/tex]

This corresponds to option (C).