The $\Delta$ G° of Atomic Oxygen Is 230 $\Delta$ S° Is 118 J/mol · K

The $\Delta$ G° of atomic oxygen is 230.1 kJ/mol, and $\Delta$ S° is 118 J/mol · K. In the stratosphere, however, the product gas-phase oxygen predominates. Why? O₂(g) 2O(g)

A) Photochemical energy of UV light drives the equilibrium forward.
B) Low pressures drive the equilibrium forward.
C) Low partial pressures make the reverse rate very small.
D) All the above are correct.