To solve the equation \( 5^x = 625 \), we first express \( 625 \) as a power of \( 5 \).
Since \( 5^4 = 625 \), we can rewrite the equation:
\[ 5^x = 5^4 \]
Now that the bases are the same, we can set the exponents equal to each other:
\[ x = 4 \]
Thus, the value of \( x \) that makes the equation true is:
A. x = 4.