Which one among the following option provide abundant reserve food materials for the development of embryo sac?

Nucellus

The correct answer is Option (4): Nucellus

The nucellus provides abundant reserve food materials for the development of the embryo sac. The nucellus is a mass of cells that surrounds the embryo sac. It contains starch, oil, and protein reserves that are used by the embryo sac to develop.

The ovary, micropyle, and integuments do not provide any reserve food materials for the development of the embryo sac. The ovary is the structure that encloses the ovule, but it does not contain any food reserves. The micropyle is the opening in the ovule through which the pollen tube enters, and the integuments are the protective layers that surround the ovule. Neither of these structures contains any food reserves.

Therefore, the answer is nucellus.