Use the Following Demand and Supply Functions: Demand $Q _ { d } = 900 - 60 p$

Multiple Choice

Use the following demand and supply functions: Demand: $Q _ { d } = 900 - 60 p$ Supply: $Q _ { s } = - 200 + 50 \mathrm { P }$ Let supply remain constant; an increase in income causes consumers to be willing and able to buy 220 more units at each price than they were previously.The new equilibrium price and quantity are

A) P = $10 and Q = 520.
B) P = $12 and Q = 400.
C) P = $10 and Q = 80.
D) P = $15 and Q = 600.