When People Make Multiple Demands Upon Themselves (When They Must

Multiple Choice

When people make multiple demands upon themselves (when they must complete or persist at multiple tasks) , their capacity for change (their willpower) sometimes seems to get "used up." Research shows that in fact, ____.

A) this effect is solely due to fatigue
B) this effect is solely due to emotions
C) this effect is solely due to attitudes about the tasks
D) willpower really does seem to get depleted; it appears that only so much willpower is available to people at a time