The heart is strengthend through cardiovascular exercise.
Option B would be your answer. The use of using steriods would then affect the form of the mens breast size. No facial hair will affect this, nor will a voice get deeper. It's only the breast that will be affected.
In both positive and negative reinforcement, the target behavior is encouraged. The method of encouragement is the difference between the two. In positive reinforcement, a pleasant consequence is added as a result of the behavior. In negative reinforcement, an unwanted or unpleasant consequence is removed as a result of the behavior.