To simplify the expression \( \frac{5^6}{5^3} \) using the quotient rule of exponents, you subtract the exponent in the denominator from the exponent in the numerator:
\[ \frac{a^m}{a^n} = a^{m-n} \]
In this case, \( m = 6 \) and \( n = 3 \):
\[ \frac{5^6}{5^3} = 5^{6-3} = 5^3 \]
Therefore, the simplified expression is \( 5^3 \).
So the correct response is:
5 cubed