Read the paragraph from the section "cellular slime molds."

single-celled organisms can aggregate to form a multicellular structure. one example is the cellular slime molds, a type of amoeba. these social amoebae will function as individual organisms when soil nutrients are present. in times of low nutrients, however, they band together into a slug-like form. they migrate together in search of food.

which word from the paragraph suggests that amoebae go through a process in which they can join together?

a. organisms
b. aggregate
c. cellular
d. function