A reversible reaction that occurs in a single step has ΔH = -45.8 kJ/(mol) and E_a = 24.7 kJ/(mol). What is the activation energy of the reverse reaction?

A) -20.9 kJ/(mol)
B) 20.9 kJ/(mol)
C) 45.8 kJ/(mol)
D) 70.5 kJ/(mol)