A catalyst lowers the activation energy of the forward reaction by $10\;kg\;mol^{-1}$ what effect it has on the activation energy of the backward reaction ?

Question

$\begin{array}{1 1} \text{increase by 10 kg $mol^{-1}$} \\\text{decrease by 10 kg $mol^{-1}$} \\ \text{Remains unaffected } \\ \text{cannot be predicted } \end{array} $