What Is the Energy of Activation, E_a, of a Reaction

What is the energy of activation, E_a, of a reaction if the rate constant, k , is 0.75 s ^{- 1} at 298 K and 11.5 s ^{- 1} at 348 K?

A) 15.8 kJ/mol
B) 20.4 kJ/mol
C) 31.4 kJ/mol
D) 47.1 kJ/mol
E) 296 kJ/mol