In which one of the following, the ovules are not enclosed by an ovary wall and remain exposed ?

The correct answer is Pinus.

Ovules are the structures that develop into seeds after fertilization. In many plants, ovules are enclosed within an ovary wall, which later forms the fruit. When ovules are not surrounded by an ovary, they are described as “naked” and remain exposed on the surface of the reproductive organ.

Among the listed groups:

• Selaginella is a lycophyte that reproduces by spores, not by seeds, and therefore does not have ovules at all.
• Funaria is a moss (bryophyte) whose life cycle also involves spores; it lacks an ovary and ovules.
• Wolffia is a tiny aquatic flowering plant (angiosperm). Angiosperms have ovules enclosed within a true ovary that becomes the fruit.

Pinus belongs to the gymnosperms, a group of seed plants whose ovules are borne on the surface of cone scales and are not surrounded by an ovary wall. The ovules stay “naked” and are directly exposed to the environment until they are pollinated.

Therefore, the plant in which the ovules are not enclosed by an ovary wall and remain exposed is Pinus.