Studies of Sport Skills Recommend Which of the Following for Optimal

Studies of sport skills recommend which of the following for optimal skill learning?

A) Break the skill down into numerous artificial units and perform the skill in different orders and at different points in the sequence.
B) When first practicing a skill, internally repeat the verbal rules as you perform the skill.
C) Practice the skill initially in artificial settings rather than a natural setting, such as start out skiing on straw before attempting snow.
D) All of these are recommended.