Why Does Ozone Not Form in High Concentrations in the Atmosphere

Why does ozone not form in high concentrations in the atmosphere above 50 km?

A) Light of the required wavelength is not available at those altitudes.
B) The pressure is too high.
C) Insufficient oxygen is available.
D) Insufficient molecules exist for removal of excess energy from ozone upon its formation.
E) Atomic oxygen concentration is too low at high altitudes.