What relationship was used to form the analogy "blood vessels are to circulatory as hair is to integumentary"?

The biological system was used to form the analogy of “hair is to integumentary as blood vessels are to circulatory”. This analogy can also refer to the relationship or function between the source and the target themselves.

In addition, an analogy is a linguistic expression or a process of transferring information from a subject to another target.

the most logical answer would be a

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.