Which of the following protects life on earth from harmful effects of UV radiations from sun?

Which of the following gases present in air protects life on the earth from the harmful effects of UV rays from the sun ?

Which of the following gases present in air to protects life on the earth from the harmful effects of ultraviolet from the sun ?

Which of the following protect us from the harmful UV-radiation coming from the sun? O_2 O_3 N_2 CO_2

Which of the following gas protects the earth from ultra violets radiation?

Which of the following is/are the harmful effect(s) of UV radiation? It causes mutation in the cell. UV radiation leads to ageing of skin. It kills many phytoplanktons. It causes global warming.