​Matthew's Baseball Coach Is Helping Him Improve His Hitting

​Matthew's baseball coach is helping him improve his hitting.During practice the coach has the pitcher throw fast balls,curve balls,and sliders so that Matthew experiences a variety of pitches,and will be more likely to hit the ball successfully during a game.Which strategy for promoting generalization is the coach using?

A) ​incorporating a variety of relevant stimulus situations in training
B) ​teaching a range of functionally equivalent responses
C) ​reinforcing occurrences of generalization
D) ​incorporating self-generated mediators of generalization