You have noticed that there is a persistent shortage of teachers in an inner-city school district in your state. Based on this observation, you suspect that:

A、there is an excess supply of teachers.;
B、the wage for teachers at those schools is lower than the equilibrium wage.;
C、the reservation price among teachers is lower than for other professions.;
D、the wage for teachers at those schools is higher than at other schools in the state.