How Do We Know That Intrinsic Motivation Is at Work

Multiple Choice

How do we know that intrinsic motivation is at work?

A) Behavior is persistent in the absence of obvious external rewards.
B) One must observe the persistence of a behavior in the absence of external rewards and behavioral alternatives.
C) One must observe that the strength of the behavior grows as a function of the amount of time devoted to the behavior.
D) The behavior must be unusual and unique to the performer.