To simplify the expression \( \frac{t^{400}}{t^{100}} \) using the Quotient Rule of Exponents, you subtract the exponent in the denominator from the exponent in the numerator:
\[ \frac{t^{400}}{t^{100}} = t^{400 - 100} = t^{300} \]
So, the simplified expression is \( t^{300} \).
The correct response is t^300.