GENERAL KNOWLEDGE

Detailed explanation-1: -Carbon, hydrogen and nitrogen were primarily responsible for the origin of life on the earth. It is believed that organic molecules could be formed by inorganic process under primitive earth conditions.

Detailed explanation-2: -Earth has enough amount of water, food, and air for the survival of living organisms.

Detailed explanation-3: -Also, the relative abundances of many elements in the universe are very different from their relative abundances on Earth. All the elements originally present on Earth (and on other planets) were synthesized from hydrogen and helium nuclei in the interiors of stars that have long since exploded and disappeared.