The following is defined as the level of organization in the body forming increasingly larger, more complex structures.

a.) cell, organ, tissue, organ system
b.) cell, tissue, organ system, organ
c.) cell, organ system, tissue, organ
d.) cell, tissue, organ, organ system

d. cell, tissue, organ, organ system

Explanation:

cells-the basic unit of life.

tissue- group of familiar cells with the same function and structure.

organ- a group of tissues of the same function and structure functioning together to perform a specific task

organ sustem- two or more organs functioning together to complete a specific process

D.) cell, tissue, organ, organ system

Explanation:

The cells are the smallest living organisms.

Those cells makeup a tissue.

Those tissues makeup an organ.

A group of organs make organ system.