The correct option is D Scutellum
The single shield shaped cotyledon of maize is called as scutellum. In maize grain, scutellum is characteristically present, which is a modified cotyledon. The scutellum is part of the structure of a seedthe modified seed leaf. The scutellum can also refer to the equivalence of a thin cotyledon in monocots. It is very thin with high surface area and serves to absorb nutrients from the endosperm during germination. The scutellum is believed to contain an as yet unidentified protein transporter that facilitates starch movement from the endosperm to the embryo.
Therefore, the correct answer is option D.