A shift of the supply curve from S to S1 could be caused by :A. an increase in the price of glass , a major input in the production of energy-efficient light bulbs.B. an increase in average income that enables consumers to buy more expensive energy efficient light bulbs instead of usual ones .C. An increase in population with purchasing powerD. An increase in the price of energy efficient light bulbs E. A decrease in the price of energy efficient light bulbs.

ow Sflows different supply curves. + 14- 13- E 12-.. . . S D 11-..... Dollars per unit C S2 10... .. B 50 100 150 200 250 300 Quantity of energy-efficient light bulbs (thousands)