Answer:
The explanatory variable is;
C. Being on a sports team
Step-by-step explanation:
Explanatory variable is the independent variable controlled/manipulated by the researcher to test its effect on the response variable.
For example:
if we want to test the effect of hours of studying on the performance of students in a test.
the hours of studying is the explanatory variable, while the performance of students in the test is the response variable.
For the given case, the high school principal wants to determine if being a member of a sports team has any impact on a student's motivation at school.
So, the explanatory variable is being a member of a sports team, and the response variable is the student's motivation at school.
Therefore, the explanatory variable is;
C. Being on a sports team