A Researcher Reports a Positive Relationship Between Sugar Consumption and Activity

Multiple Choice

A researcher reports a positive relationship between sugar consumption and activity level for a group of 8-year-old children.However,the researcher cannot be sure whether the extra sugar is causing the children to be more active or whether the extra activity is causing the children to eat more sugar.This is an example of

A) the third-variable problem.
B) the directionality problem.
C) the reversal problem.
D) the criterion problem.