For an Equilibrium Reaction with K = 1 $\times$ 10⁸, the Forward Rate Constant Was Found to Be 3

For an equilibrium reaction with K = 1.2 $\times$ 10⁸, the forward rate constant was found to be 3.5 $\times$ 10⁵. What is the value of the reverse rate constant?

A) 3.5 $\times$ 10⁵
B) 3.4 $\times$ 10²
C) 4.2 $\times$ 10¹³
D) 2.9 $\times$ 10^-3
E) 6.0 $\times$ 10^-5