Which relationship can best be described as causal?
(1) the alarm goes off and the sun rises.
(2) the car is moving slowly and the driver is singing.
(3) the snow is falling and the stores run out of snow shovels.
(4) the birds are chirping and the rain is coming down.

3) The snow is falling and the stores run out of snow shovels. This relationship can best be described as causal.

A causal relationship is a relationship between two events wherein the occurrence of the first events gives rise to the second event. The first event causes the second event to happen.

The falling snow is the first event, had it not happened, it would not have resulted to the second event which is the stores running out of snow shovels.

The answer is mathg.a.y