FIGURE 3-1 -Refer to Figure 3-1. a Shift of the Demand Curve

FIGURE 3-1
-Refer to Figure 3-1. A shift of the demand curve for energy-efficient light bulbs from D to D1 could be caused by

A) a decrease in the price of ordinary light bulbs.
B) a news bulletin stating that energy-efficient light bulbs emit a harmful gas.
C) a decrease in the price of energy-efficient light bulbs.
D) an expectation that government regulation will soon prohibit the use of ordinary light bulbs.
E) a change in preferences toward ordinary light bulbs.