Which graph represents a density curve, and why?
A
neither graph A nor graph B, because, even though both curves are above the horizontal axis, their areas are not the same valueB
graph B only, because the area under the curve equals 2, and the curve is above the horizontal axisC
both graph A and graph B, because both curves are above the horizontal axis, and their areas are positiveD
graph A only, because the area under the curve equals 1, and the curve is above the horizontal axis