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 D2 could be caused by

A) an increase in the price of ordinary light bulbs.
B) a change in preferences away from ordinary bulbs to energy-efficient bulbs.
C) an expectation that new government regulation will require the use of energy-efficient light bulbs only.
D) a decrease in the price of energy-efficient light bulbs.
E) a news bulletin stating that energy-efficient light bulbs emit a harmful gas.