The Efforts to Interdict Supplies of Illicit Drugs Around the World

The efforts to interdict supplies of illicit drugs around the world in the last part of the 20th century have resulted in

A) the availability of such compounds remaining about the same as before.
B) a slight decrease in the availability of illicit drugs in the last decade.
C) an increase in the availability of illicit drugs in the past decade.
D) no major change in methods of drug transport for high level drug dealers who provide illicit drugs for local consumption.