Which sequence represents the correct order of levels of organization found in a complex organism?
a. cells → organelles → organs → organ systems → tissues
b. tissues → organs → organ systems → organelles → cells
c. organelles → cells → tissues → organs → organ systems
d. organs → organ systems → cells → tissues → organelles

C is the answer.

Explanation:

Organelles (the smallest in this situation) are what you can find inside a cell (example: nucleus, mitochondria, etc..).

Cells are what make up tissues (such as muscles).

Tissues make up organs (such as the heart) and organs make up organ systems (such as the circulatory system).

cell regulation is conducted by special proteins.

the statement is true