sample COV

A sample covariance of two random variables is most commonly utilized to: A) calculate the correlation coefficient, which is a measure of the strength of their linear relationship. B) identify and measure strong nonlinear relationships between the two variables. C) estimate the “pure” measure of the tendency of two variables to move together over a period of time. Your answer: A was correct! ------- i picked A and knew that was the most likely answer but why is C wrong? COV depends on the units to determine its strength of relationship, so it is a “pure” measure…so i dont see why it is wrong.

ok nevermind. it said MOST utilized…what a stupid question.