Which pair of variables has a clear causal link?
a.sales of hot dogs and cold coffee at a snack bar
b.the number of road accidents and the number of vegetarians in a city
c.the amount of snowfall and the number of wins for a hockey team
d.the number of units sold by an appliance company and its annual revenues

Respuesta :

D has a clear casual link
D.

The relationship between these two variables is clear, as the units sold will increase, the annual revenue will increase.