The correct option is B viviparous
In viviparous animals, well developed young ones are born from the female organism at the end of a gestation period. In this scenario, there is no fear of predator and the environmental elements as in case of oviparous animals, that lay eggs and young hatch from it.
Viviparous mode of development is not affected by adverse environmental conditions. Therefore the chances of survival of the young one is greater in viviparous animals.