Final answer:
Even if variables are correlated, a third variable might explain the observed changes without there being a direct cause-and-effect relationship between the two originally considered variables, which demonstrates that correlation does not necessarily indicate causation.
Step-by-step explanation:
Even if variables are correlated, a change in one variable might not be caused by a change in another variable because of a third variable. The correct answer is c. Because of a third variable. To illustrate, imagine that ice cream sales and the rate of burglaries increase simultaneously. This does not necessarily mean that one causes the other; it is more plausible that they both increase due to a third factor such as warmer weather. This common third factor, known as a confounding variable, can explain why the two variables are moving together without having a direct causal relationship. Hence, correlation does not imply causation, and careful analysis must be undertaken to determine if there is a true cause-and-effect relationship.