Answer:
a. increase
b. supply
c. decrease
d. increase
e. demand
f. increase
Explanation:
An increase in demand will cause an increase in the equilibrium price and quantity of a good so (a) is increase.
Since a decrease in supply will cause an increase in the equilibrium price and a decrease in the equilibrium quantity of a good so (b) (c) and (d) are supply, decrease and increase respectively.
Also a change in demand will cause equilibrium price and output to change in the same direction. Therefore (e) and (f) are demand and increase respectively.