Studies have shown that children in the U.S. who have been spanked have a significantly lower IQ score on average than children who have not been spanked.
a. Identify the explanatory variable in these studies. Also classify this variable as categorical or quantitative.
b. Identify the response variable in these studies. Also classify this variable as categorical or quantitative.

c. Identify a confounding variable that provides an alternative explanation for the lower average IQ score for children who have been spanked, compared to those who haven’t.