Dr Peterson uses a correlation study to determine if time spent play video games is related to obesity. The objective of this research is:
A. to describe the occurrence of a phenomenon
B. to explain why people play video games
C. to randomly assign participants to different conditions, then use hypothesis testing to make inferences about how these conditions influence behavior
D. to formally test whether a relationship exits between two or more variables
E. I am unfamiliar with this concept and to answer would be merely a guess.