Consider the following reversible reaction

The right choice is  K(eq) = ([CO₂]) / [O₂]

Explanation:

The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium

For a system undergoing a reversible reaction described by the general chemical equation

An equilibrium constant can be expressed as following

K(eq) = ([X]ˣ*[N]ⁿ) / ([A]ᵃ*[B]ᵇ)

where [] is the equilibrium concentration of each component.

and the concentration of solid is conventionally considered as 1

in your example:

The reversible reaction

taking in consideration that C is a solid and the concentration of solid is conventionally considered as 1

So,  the equilibrium constant for this reversible reaction can be expressed as following

∴ The right choice is  K(eq) = ([CO₂]) / [O₂]

sup bro, im dumb, but this is what i found xd

"the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface"