One problem of maintaining a physical activity regime is that once people stop for a few days, they never start again. This is an example of

A) a lack of self-control.
B) the abstinence violation effect.
C) influences from the environment.
D) a lack of sufficient social support.

The abstinence violation effect refers to the tendency for individuals to abandon their efforts to maintain a behavior change once they have experienced a minor lapse or setback. This may be due to feelings of guilt or a sense of failure, which can lead to a perceived loss of control over the behavior.