The 'study of alien life' is known as:

Correct answer: (c) Xenobiology

Explanation

Xenobiology (from the Greek *xenos*, "stranger" or "foreign") is the study of alien forms of life. The study of possible life on other planets is also called astrobiology or exobiology. Xenobiology is also used for the making of life forms with unnatural biochemistry in the laboratory.

Zoology is the study of animals, and biochemistry the study of chemical processes in living things on Earth.