How might microorganisms be spread?

Asexual reproduction

Explanation:

for microorganism to reproduce and spread, the microorganism uses a process of cell division called mitosis, where the microorganism divides it self into two individual microorganism by mitosis using Asexual reproduction (an organism dividing itself into 2 individual organism not involving sexual activities, called Asexual reproduction). for these microorganisms to be able to reproduce Asexually that makes it much faster for these organisms to spread much more faster then mammals of other Sexually reproductive organisms.

the answer would be c

dynamic equilibrium is the answer.