An air-filled parallel-plate capacitor is charged to a potential difference \(\Delta V_0\) by a battery and then disconnected from the battery.

In Trial 1, the capacitor is connected across a resistor of resistance \(R\), and the time \(t_1\) required for the charge on the capacitor to decrease to half of its initial value is measured.

In Trial 2, an identical air-filled capacitor is charged to the same potential difference \(\Delta V_0\) and disconnected, but a slab of dielectric material with dielectric constant \(\kappa > 1\) is fully inserted between the plates before the capacitor is connected across the same resistor \(R\). The time \(t_2\) required for the charge to decrease to half of its initial value is measured.

Which of the following correctly compares \(t_2\) to \(t_1\) and provides a correct justification?