Why Is It So Important to Set Appropriately Challenging Goals

Why is it so important to set appropriately challenging goals?

A) Setting unattainable or overly challenging goals may lead to discouragement and a withdrawal of effort
B) The more challenging a goal, the more likely the athlete is to rise to the challenge and meet the goal
C) Appropriately challenging goals tend not to require short-term goals
D) Setting appropriate goals is correlated with higher levels of extrinsic motivation