Something that is prevalent happens

Question

a. very rarely
b. occasionally
c. often

Answer 1

c. often

Answer 2

In which sentence below is in the word in * a predicate nominative?
a. Carmen is very *interested* in science, especially biology and anatomy.
b. Carmen plans to pursue a *career* as a doctor.
c. Carmen is a *volunteer* at the hospital.

Answer 3

c. Carmen is a *volunteer* at the hospital.