Steph Social Planner knows that the PMB for acquiring a university degree is

250 - Q (where Q is the total number of persons obtaining a university degree). The SMB is 500 - Q. Also PMC = SMC = 100. Steph knows that to have the efficient number of persons obtain a university degree it will be necessary to:

a) Set a maximum limit on the number of persons obtaining a university degree equal to 400.

b) Impose a tax of 250 on each individual who obtains a university degree.

c) Provide a subsidy of 250 to each individual who acquires a university degree.

d) Require that at least 150 persons obtain a university degree.