Explanation:

 Oviparous animals lay fertilized or unfertilized eggs .the fertilised eggs remain covered by hard calcareous shell and laid in safe place in environment during incubation period and chances of their survival is less than viviparous.
Viviparous animals gave birth to young ones .the fertilized egg(zygote) develop inside the body of female and hence chances of survival of young one is more because of proper embryonic care and protection in the womb.