Market Demand Is Given as Q_D = 80 - 2P

Market demand is given as Q_D = 80 - 2P.Market supply is given as Q_S = 2P.In a perfectly competitive equilibrium,what will be price and quantity traded in the market

A) price will be $20 and quantity will be 10
B) price will be $20 and quantity will be 40
C) price will be $10 and quantity will be 20
D) price will be $40 and quantity will be 20