The structure of soybean seeds includes radicle, embryo, hypocotyl, cotyledon and seed coat. The seed coat plays a protective role. Embryo will develop into stem and leaf, radicle will develop into root and hypocotyl will develop into the part connecting root and stem. When the seeds germinate, the radicle of the embryo will grow long, the seed coat will protrude and develop into a young root. At the same time, the hypocotyl under the cotyledon will grow rapidly and develop into a white and tender part connecting the root and stem.

So choose C.