How does disgust act as a behavioral immune system?

What will be an ideal response?

a . Disgust produces an avoidance motive. When we see something disgusting, we want to avoid it.
b. In our ancestral history, this helped us to avoid spoiled food, contact with sick people, risky sex partners, and other potentially health-damaging experiences.
c. Disgust may even underlie some modern tendencies toward prejudice. In the past, people living in the same community had likely been exposed to the same diseases. Strangers from other groups could carry new, risky diseases. Disgust with other groups is associated with prejudice in modern intergroup relations.