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An atmospheric chemist is investigating the reaction below for the production of ozone (O₃) in the stratosphere:

3 O₂(g)  2 O₃(g)

From the following standard half cell potentials:
O₃(g) + 2 H⁺ + 2 e O₂(g) + H₂O(l) E°=2.07V
O₂(g) + 4 H⁺ + 4 e 2 H₂O(l) E°=1.23V

The temperature of the stratosphere is -60°C. The K_c at this temperature is:
A. 3.33 *10^-80
B. 1.54 *10^-70
C. 0.83
D. 3.00 *10⁷⁹

Here's the work that I did:
E°=1.23V-2.07V=-.84V
nFE=RTln(K):
(4 mol e)(96485 C/mol e) (-.84V)=(8.31447J/mol*K)(273-60K)lnK
K=3.2*10^-80

As this is pretty close to A, I put that down. The answer, though, is B. Is there something I missed?

Thanks!