Judith has been complaining of pain in her lower back. her friends suggested that judith change the heel height of her shoes. judith began wearing a lower heel, but still continued to experience pain in her lower back. in this case, the relationship between judith's back pain and the heel height is representative of a correlation.

no correlation

Explanation:

There are different kind of correlations, the positive one is when one variable increases, the other one, also increases.

A Negative one is when a variable increases, the other variable decreases. Judith´s friends thought this will be the result but it was incorrect.

A no correlation like in this case, neither increases or decreases the other variable, because with or without heels the pain is steady.

answer(b) keep oxygenated and deoxygenated blood separate;