A Prestigious Private High School Requires Each of Its Teachers

Multiple Choice

A prestigious private high school requires each of its teachers to have a Ph.D.in the subject they teach.Which effect is this requirement likely to have

A) an increase in the supply of teachers to this school
B) an increase in wages for teachers at the private school, relative to those at public schools
C) a decrease in the marginal product of teachers at the private school
D) an increase in the demand for teachers by this school