Last year, the world demand curve for copper shifted rightward due to continued economic growth in China and other emerging economies. Also, the supply curve for copper shifted leftward due to strikes and other labor disruptions at some of the copper mines. As a result, we observed:
A.
higher equilibrium copper prices and unambiguously lower quantities.
B.
higher equilibrium copper prices and unambiguously higher quantities.
C.
higher equilibrium copper prices and either higher or lower quantities.
D.
lower equilibrium copper prices and either higher or lower quantities.