An example of a government-imposed barrier to entry

a. a quota on imports.
b. occupational licensing.
c. economies of scale.
d. both a and b.
e. all of the above.

why would the government be willing to erect barriers to entering an industry? the government would be willing to impose barriers

a. encourage firms to carry out research and development of new and better products.
b. protect the public from incompetent practitioners.
c. protect u. s. firms from international competition.
d. both a and b.
e. all of the above.