In which of the following pairs of tissues does mitosis occur?
A)Muscles and epithelial tissue.
B)Ovaries and testes.
C)Muscles and ovaries.
D)Testes and glands.

Mitosis occurs in response to the body's need for growth and repair. Generally, it occurs in all tissues except mature nerve tissue and in the formation of gametes.

Explanation:

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.