Which One of the Following Alternatives Most Clearly Illustrates General

Which one of the following alternatives most clearly illustrates general, as opposed to specific, transfer?

A) The skills Arnold has developed as a marathon runner helps him later in life when he jogs for exercise.
B) Brian has learned study skills in his sociology class that he also finds useful in his nutrition class.
C) Connor's knowledge of addition and subtraction helps him balance his checkbook.
D) Dave's knowledge of the human digestive system helps him understand the digestive system of an earthworm.