Hint: Vivipary is a type of reproductive adaptation shown by mangroves where seeds or embryos begin to develop before they detach from the parent. The embryo gets nourishment from the parent plant and grows out of seed in the form of a green seedling.
Plant vivipary is the process of giving birth to young seedlings in advanced stages of development. It is commonly seen in mangroves like Rhizophora , Sonneratia and Heritiera. Mangroves show adaptation to survive in harsh, unstable environments with low oxygen and varying salinity of soils. The salinity of the surrounding soil damages the seeds if they fall in their early stages. In such an environment, if seeds are dispersed then their chances of survival are very less. Therefore, mangroves show vivipary.
In such plants seed dormancy is absent. The embryo of seed continues to grow while present inside the seeds which are still present in the fruits attached to the parent plant. The hypocotyl increases in sizes and pushes the radicle out of seed and fruit which makes the seedling heavy. This breaks connection with the fruit and falls down vertically in the soil in such a way that the plumule remains outside the salty water. Then, the radicle produces roots quickly that fixes the seedling firmly in the soil.
Among the given options:
Xerophytes are terrestrial plants which have adapted well to survive in extreme habitats of desert where water availability is low. Seeds of such plants are modified to store more water before germination, so to make sure that there is sufficient supply of water for seedling survival. Hence, xerophytes do not show vivipary.
Hydrophytes are plants which are adapted to survive in water.
Such plants show various reproductive adaptations, for example, they produce light buoyant seeds that can float on the surface of water.
After germination, plants grow quickly and form an extended shoot on the water surface.
Therefore, hydrophytes do not show vivipary.
Epiphytes are also called “air plants” as they are not anchored in the soil. They are not parasites as they can make their own food. Epiphytes derive nutrients from air, rain and from other sources. Epiphytes show reproductive adaptations as; they produce colourful flowers with strong nectar to attract many pollinators. After pollination and fertilization, they produce numerous small seeds which can be dispersed by wind. Thus, epiphytes do not show vivipary.
So, the correct answer is option C.
Note: The definition of viviparous is producing young ones. In plants, this is the production of new plants while still on the parent plant. In viviparous germination the seeds get germinated being attached to the parent plant.