A.

coleorhiza

In a cereal grain (e.g., wheat), the single cotyledon of embryo is represented by the scutellum. Scutellum is specialized for nutrient absorption from the endosperm.
Coleoptile is a modified ensheathing leaf that covers and protects the young primary leaves of a grass seedling.
Coleorhiza is a sheath-like structure found on the radicle which covers and protects it during the growth into the soil.

B.

Autogamy and geitonogamy

B.

Entomophily

Insect pollinated plants provide rewards as edible pollen grain and nectar as usual rewards. While some plants also provide safe place for deposition of eggs.

D.

Fungi

A.

α-amylase

Barely seeds are rich in carbohydrate (Starch). The starch is hydrolysed by α-amylase to monosaccharides unit at the time of germination of seeds.