The graph below shows the price, y, in dollars, of different amounts of granola, x, in pounds:

a graph titled granola prices shows number of pounds on x axis and price in dollars on y axis. the scale on the x axis shows numbers from 0 to 12 at increments of 2, and the scale on the y axis shows numbers from 0 to 48 at increments of 8. a straight line joins the ordered pairs 0, 0 and 12, 48

which equation best represents the relationship between x and y?

a) y = 8x
b) y = x + 4
c) y = 4x
d) y = x + 8