Please Help!!! Which correlation is most likely a causation?

A. the positive correlation between the height of a person and the number of pairs of socks he owns
B. the positive correlation between the number of windows in a building and the number of steps in a building
C. the negative correlation between the number of safety classes employees attend and the number of accidents in the company
D. the negative correlation between the sales of vacuum cleaners and the sales of boots in a store