Suppose the population's income increases, shifting the demand curve to the right. Now the demand curve for tangelo oranges becomes Qd = 4000-2P. The supply curve remains the same. Qs = 3P. The new equilibrium price and quantity in the market are:
a. P=800, Q=2400.
b. P=2200, Q=1100.
c. P=500, Q=500.
d. P=100, Q=250.