Which of the following is true of affirmative action programs?

a$.$ Affirmative action is near the end of its useful life.

b$.$ Affirmative action programs are only for underrepresented groups and people with disabilities.

c$.$ Employers are not required to have quotas for hiring certain groups.

d$.$ Affirmative action often requires quotas to help correct the under$-$utilization of certain groups.