On Even-Numbered Days, a Rat Receives Morphine Injections in a Room

Multiple Choice

On even-numbered days, a rat receives morphine injections in a room with striped walls, low illumination, and a musty scent. On odd-numbered days, the rat receives saline injections in a room with light yellow walls, bright illumination, and a cinnamon scent. Over a period of three weeks, the morphine dosage, administered in the striped room, is increased incrementally. At the end of three weeks, the highest dose of morphine administered is administered on an odd-numbered day in the yellow room. While the rats have shown an increased tolerance to morphine in the striped room, two-thirds of the rats that receive the same dose in the yellow room die of cardiac failure. Their deaths can be attributed to

A) proactive interference.
B) retroactive interference.
C) trace decay.
D) retrieval failure.