If the purchase and sale of a currently illegal drug (for example, marijuana) were decriminalized, economists would expect:
a. an increase in demand and supply of this drug.
b. an increase in demand and a decrease in the supply of this drug.
c. a decrease in demand and an increase in the supply of this drug.
d. a decrease in demand and supply of this drug.
In this case, if marijuana were to decriminalized, demand would be skyrocket in the short-term. It will achieve equilibrium once it is set to be recreational use only.