The Maxwell–Boltzmann distribution curves for a fixed amount of gas at two different temperatures, $T_1$ and $T_2$, are shown below.

Which of the following statement(s) correctly explain(s) why the rate of reaction is greater at temperature $T_2$ than at $T_1$?

1. The activation energy, $E_a$, decreases at the higher temperature $T_2$.
2. The area under the curve to the right of $E_a$ is larger at $T_2$ than at $T_1$.
3. The frequency of collisions between reactant molecules increases because the molecules have a higher mean kinetic energy.