The graph below shows the relationship between the number of minutes Ray walks and the number of calories (y) Ray burns when he walks for x minutes. Which equation can be used to find the number of calories Ray burns when he walks for minutes?

A
y = x +4
B
y = x/4

C
y = 4x
D
y = x-4

The equation that can be used to find the number of calories Ray burns when he walks for x minutes is:

C) y = 4x