The Most Important Function of the Ozone Layer in the Stratosphere

The most important function of the ozone layer in the stratosphere is

A) Conversion of oxygen to O_3.
B) Destruction of CFCs, that otherwise would accumulate in the atmosphere and cause increased incidence of lung cancer.
C) Absorption of incoming UV radiation from the sun, that otherwise would increase the risk of skin cancer.
D) Maintenance of the Earth's magnetic field.