In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument(s), forming its outer layer(s), the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center.

**Answer:**

The correct answer is option 'D', which states that the archesporial cell differentiates from the nucellus hypodermally in the micropylar region of the ovule.

The ovule is the structure within the ovary of a flower that develops into a seed after fertilization. It consists of several layers of tissue, including the nucellus. The nucellus is the central part of the ovule that surrounds the embryo sac, which houses the female gametophyte.

The differentiation of the archesporial cell is a crucial step in the development of the ovule. It gives rise to the cells that will eventually become the megaspores, which will go on to form the female gametophyte.

Below is a detailed explanation of why option 'D' is the correct answer:

**1. Hypodermal location:**
The archesporial cell differentiates from the nucellus in the hypodermal region of the ovule. This means that it is located below the surface layers of the nucellus.

**2. Micropylar region:**
The archesporial cell specifically differentiates in the micropylar region of the nucellus. The micropyle is the opening at the apex of the ovule, through which the pollen tube enters during fertilization. The micropylar region is located near this opening.

**3. Development of archesporial cell:**
The archesporial cell is a single cell that gives rise to the megaspore mother cell (MMC). The MMC undergoes meiosis to produce four haploid megaspores. Three of these megaspores degenerate, and only one survives to develop into the female gametophyte.

**4. Importance of archesporial cell differentiation:**
The differentiation of the archesporial cell from the nucellus is a crucial step in the development of the ovule. It marks the beginning of female gametophyte development and eventually leads to the formation of the embryo sac, which contains the egg cell and other cells required for fertilization.

In conclusion, the archesporial cell differentiates from the nucellus hypodermally in the micropylar region of the ovule. This process is essential for the development of the female gametophyte and subsequent seed formation.

The nucellar cells at the micropylar end increases leading to initiation of archesporial cells formation from ovule primordium in the hypodermal region.

So, the correct option is D