To simplify \( \frac{23^{65}}{23^{32}} \) using the quotient rule of integer exponents, we apply the rule which states that:
\[ \frac{a^m}{a^n} = a^{m-n} \]
In this case, \( a = 23 \), \( m = 65 \), and \( n = 32 \). So we calculate:
\[ \frac{23^{65}}{23^{32}} = 23^{65 - 32} = 23^{33} \]
Thus, the simplified form is \( 23^{33} \).
The correct answer is C. \( 23^{33} \).