Pat Notices That When Thunder Can Be Heard in the Distance,her

Multiple Choice

Pat notices that when thunder can be heard in the distance,her dog,Rudy,hides under her desk,and she believes that the thunder causes Rudy to hide.Her friend Gregg points out that there are other changes associated with thunder,including changes in barometric pressure.Gregg has pointed out a(n) ____.

A) random variation
B) control factor
C) covariation bias
D) third variable problem