What is the strongest relationship you can infer between two variables from this statement?

the number of minutes you can talk on a cell phone decreases as the phone's battery charge decreases.

causation

correlation

association

no relationship

The correct answer is:

Causation.

Explanation:

As the battery charge of a phone decreases, the amount of time you can perform any action with the phone decreases, including the number of minutes you can talk. This is because after a certain amount of time, there will be no more battery charge, which means you will not be able to use the phone at all.