Occasionally, $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ may lead to pure monopoly; in other market conditions, they may limit competition $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$

Question $16$ options:

a$)$

barriers to entry; to a few oligopoly firms

b$)$

barriers to entry; to a natural monopoly

c$)$

deregulation; requiring new patent law

d$)$

deregulation; requiring new copyright law