Recently in a small city, building contractors lobbied the city munipality to pass a law requiring all people working on residential dwellings be licensed. Why would the contractors lobby for this requirement?

a$.$

to reduce the cost of building dwellings

b$.$

There is no good explanation for this type of lobbying.

c$.$

to guarantee that work on dwellings is of high quality

d$.$

to create a legal barrier to entry