A line between a planet and the sun sweeps out two equal areas at different places as it moves
along its orbit. Which factor remains constant as this happens?

I think the answer has to be D/ the distance from the sun to the planet while it sweeps out the area

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]