Which one of the following is not associated with megasporangium?

The correct answer is Option (3) → Generative cell

The megasporangium is the ovule. It is the female structure of the flower that forms the megaspores and the embryo sac.

Option (1) Funicle — Associated with the megasporangium. The funicle is the stalk that joins the ovule to the placenta.

Option (2) Integument — Associated with the megasporangium. The one or two integuments are the protective envelopes of the ovule. After fertilisation they become the seed coats.

Option (3) Generative cell — Not associated with the megasporangium. The generative cell belongs to the pollen grain, the male gametophyte. It is the small cell that divides to form the two male gametes.

Option (4) Micropyle — Associated with the megasporangium. The micropyle is the small opening at the tip of the ovule, where the integuments do not meet. The pollen tube usually enters the ovule through it.

NCERT Extract:
The Pistil, Megasporangium (ovule) and Embryo Sac – “… The Megasporangium (Ovule) : Let us familiarise ourselves with the structure of a typical angiosperm ovule (Figure 1.7d). The ovule is a small structure attached to the placenta by means of a stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Thus, hilum represents the junction between ovule and funicle. Each ovule has one or two protective envelopes called integuments. Integuments encircle the nucellus except at the tip where a small opening called the micropyle is organised. Opposite the micropylar end, is the chalaza, representing the basal part of the ovule.”
Stamen, Microsporangium and Pollen Grain – “… The generative cell is small and floats in the cytoplasm of the vegetative cell.”