Germination process of kidney bean seeds: the energetic seeds begin to breathe after absorbing water, and the nutrients in cotyledons begin to transport to radicle, embryo and hypocotyl. After a certain period of time, the radicle breaks through the seed coat, exposing the radicle and forming the main root. At the same time, the cells of hypocotyl also grow and elongate correspondingly, and the embryo or embryo is pushed out of the soil together with cotyledons, and the embryo protrudes from the soil to form stems and leaves.

So choose: D.