This Graph Illustrates the Marginal Cost,marginal Private Benefit,and Marginal Social

This graph illustrates the marginal cost,marginal private benefit,and marginal social benefit of immunization against a contagious childhood disease.
If school districts imposed a rule that all children must be immunized to enroll,and 300 children are school-aged

A) the number of immunizations would be efficient,but the entire cost would fall on the parents.
B) too few children would be immunized.
C) the number of immunizations would be efficient,but the cost to taxpayers would be unjustifiable.
D) too many children would be immunized.