Which of these is an advantage of multicellular organisms?

a. one cell performs all of the necessary functions.

b. all of the cells are the same.

c. they can reproduce quickly.

d. they can grow.

The correct answer is option D. They can grow.

Explanation:

Multicellular organisms are formed by the binding and functioning of cells together by forming the different levels of the system. The different level systems are tissue, Organ, organ system and complete individual. When cells join or connect together they form tissue and tissues connect to make organs and a bunch of organs make an organ or function system.

So, the multicellular organism grows according to their level of organization from tissue level to organ system.

Thus, the correct answer is option D. they can grow.