The Maxwell–Boltzmann energy distribution curves for a reactant mixture under two different temperatures are shown below. Two possible activation energy thresholds, $E_1$ and $E_2$, are also indicated.

Which row in the table correctly identifies:

1. the curve representing the reaction mixture at the higher temperature,
2. the activation energy threshold for the catalysed reaction, and
3. the effect of increasing temperature on the value of the activation energy ($E_a$)?