Estelle is raking leaves in her yard. After 1 hour, she has 2 bags of leaves. After 3 hours, she has 6 bags of leaves. Which graph represents Estelle's leaf raking progress? a: graph of line going through (0, 0) with a slope of 2 b: graph of line going through (0, 2) with a slope of 2 c: graph of line going through (0, 0) with a slope of 3 D: graph of line going through (0, 3) with a slope of 3