A. Seed in many members of the Euphorbiaceae, such as castor, the soft outgrowth capping the hard seed is formed by proliferation of the cells at the tip of the outer integument called caruncle. It is rich in starch and sugars.

B. Cotyledons-  They  are thin, semi-transparent and oval in outline in castor. They have palmate venation. The middle costa or rib is more prominent and bears a few lateral veins.

C. Funiculus- It is a stalk like structure which attaches the ovule to the placenta.

D. Inner integument- It forms the tegman, inner covering of seed.

So, the correct answer is ‘Outer Integument’.