The scatter plot shows the relationship between the weekly hours spent on social media and the weekly hours spent reading, by the students of a middle school:

what is the y-intercept of the line of best fit and what does it represent?

6 hours; the number of hours students read when they do not spend time on social media
6 hours; the number of hours students spend time on social media when they do not read
8 hours; the number of hours students read when they do not spend time on social media
8 hours; the number of hours students spend time on social media when they do not read