In the central sac of an embryo, a primary endosperm nucleus is present from which endosperm is developed. The primary endosperm nucleus is formed when one male gamete fuses with a secondary nucleus and this fusion is called triple fusion. They provide an essential nutrient to the embryo. The residual nucellus that persists in the seed is called perisperm. The caruncle is formed when cells present at the tip of the outer integument become enlarged and form a fleshy outgrowth at the micropylar side of the seed. It helps in seeds dispersal. The endosperm, perisperm is found in all four options mentioned above but the caruncle is present only in castor.