Which of the following best characterizes Harvard et al's attitude toward utilizing value judgments in health$-$oriented modeling?

a$.$ It is a totally avoidable component of model building and it SHOULD be avoided.

b$.$ It is a fundamental, unavoidable component of model building.

c$.$ It is a common, but avoidable component of model building.

d$.$ While it is avoidable, it should NOT be avoided.