Embryo sac occurs in

The correct option is C

Ovule

The correct option is C.

Explanation for correct option:

1. The embryo sac also known as the female gametophyte is present in the ovule.
2. It consists of one central cell containing two polar nuclei, three antipodal cells at the chalazal end, and one egg cell along with two synergid cells at the micropylar end.
3. It is also referred to as a seven-celled, eight-nucleate structure.

Explanation for incorrect options:

Option A:

1. The fusion of male and female gametes produces a zygote which develops into an embryo.
2. It is the new plant that is protected by the seed.

Option B:

1. Plumule, radicle, epicotyl, hypocotyl, and cotyledons constitute the embryonic axis.
2. When the seed germinates, the plumule gives rise to the shoot system and the radicle gives rise to the root system.
3. The region between the attachment points of the cotyledons, also called the cotyledonary node and the plumule is called epicotyl.
4. The region between the cotyledonary node and the radicle is called the hypocotyl.

Option D:

The endosperm is present inside the seed which provides nutrition to the embryo to initiate germination.

Final answer: Embryo sac occurs in the ovule.