The correct option is A Crocodilus
Vipera (viper snake) belongs to sub-order ophidia of class Reptilia and possess three chambered heart.
Testudo (Tortoise) belongs to order chelonia of class Reptilia, possess three chambered heart.
Bungarus (Krait snake) belongs to sub-order ophidia of class-Reptilia, possess three chambered heart.
Crocodilus (crocodile) possesses four chambered heart