Which of the following compounds is an example of Freon?

Given below are two statements:

Statement I : If BOD is 4 ppm and dissolved oxygen is 8 ppm, then it is a good quality water.

Statement II : If the concentration of zinc and nitrate salts are $$5 ~\mathrm{ppm}$$ each, then it can be a good quality water.

In the light of the above statements, choose the most appropriate answer from the options given below :

The delicate balance of $$\mathrm{CO}_{2}$$ and $$\mathrm{O}_{2}$$ is NOT disturbed by :

Match List I with List II

Choose the correct answer from the options given below :