Research has suggested that there is a correlation between Internet usage and obesity. Using this information, a study found a correlation of r = 0.79 between the number of hours of daily Internet usage and Body Mass Index, a measure of body weight. Which of the following is true? Group of answer choices There is a pretty strong positive linear relationship between the number of hours spent on the Internet and the Body Mass Index scores. Using the Internet causes people to gain weight. Physical activity is a possible "lurking" variable behind this relationship, since people who spend a large amount of time using the Internet may be more likely to be less physically active