Comparing the blue bars (8 - 12 yrs old) and orange bars (13 - 17 yrs old), we can see that most of the blue bars centered between 1 - 1.9 hours of screen time while the orange bars somehow centered between 3 - 3.9 hours of screen time.
If more screen time mean less exercise, then, we can infer that on average, 13 to 17-year-olds gets less exercise compared to 8 to12-year-olds. (Option 3)