In the atmosphere, under the effect of ultraviolet rays, oxygen molecules combine to form ozone molecules, and ozone molecules also photodissociate to form oxygen molecules. Which of the following would be observed if this reaction is in dynamic equilibrium?

3 O2 <--> 2 O3

a
The rates of the forward and reverse reactions will remain the same.

b
The concentration of ozone (O3) will decrease.

c
The concentration of oxygen (O2) will increase.

d
The rates of the forward and reverse reactions will increase.