The correct answer is option 'D', Epicotyl.

Explanation:
The embryonal axis is the part of the embryo that gives rise to the main shoot system of the plant. It consists of three main regions: the radicle, the hypocotyl, and the epicotyl. The radicle is the embryonic root, the hypocotyl is the region between the radicle and the cotyledons, and the epicotyl is the region above the level of the cotyledons.

The epicotyl is the uppermost part of the embryonal axis, located above the cotyledons. It is responsible for the development of the stem and leaves of the plant. The epicotyl elongates after germination and emerges from the soil, giving rise to the shoot system.

The epicotyl plays a crucial role in the growth and development of the plant. It contains the apical meristem, which is responsible for the production of new cells and tissues. The apical meristem is responsible for the primary growth of the plant, leading to the elongation of the stem and the production of leaves and branches.

In addition to the apical meristem, the epicotyl also contains leaf primordia, which will later develop into mature leaves. These leaf primordia are arranged in a specific pattern known as phyllotaxy, which determines the arrangement of leaves on the stem.

Overall, the epicotyl is an important region of the embryonal axis as it gives rise to the shoot system of the plant and is responsible for the growth and development of the stem and leaves.