An Observational Study Is Done to See If Eating at Least

Multiple Choice

An observational study is done to see if eating at least two apples a week helps prevent tooth decay in children. However, the researchers are aware that children who eat apples may also drink less soda, so they measure soda consumption as well. In this example, soda consumption is an example of

A) an interacting variable.
B) an explanatory variable.
C) a response variable.
D) a confounding variable.