"what changes have occurred in the lobbying environment over the past three or four decades?
a) there is more professional lobbying.
b) many interests lobby both the national government and the states.
c) a fragmentation of interests has taken place.
d) all the above"

D) All of the above

Explanation:

Lobbying has become a very widespread and powerful industry in the United States. According to several estimates, there are around 20 lobbysts per congress person in the United States, which says a lot about the power of lobbying.

Lobbying has spread to practically every industry: from energy, to logging, to banking, practically every sector in the economy has lobbysts in Washington and in state capitals representing their interests.

can you explain it better