How does a virus cause disease?
A It disrupts homeostasis and equilibrium in the body.
B It produces toxic substances that harm the body.
C It rapidly undergoes mitotic cell division that quickly smothers nearby cells.
D It form endospores in the body.

It produces toxic substances that harm the body.

Explanation:

Virus cause disease when it replicate rapidly to destroy the cells of the body by the production of toxic substances. It quickly replicate and destroy the cells of immune system to get hold on the body.

i think the answer is

mass