Which one of the following categories of animals is correctly described with no single exception in it?
A. In chondrichthyes notochord is persistent throughout life.
B. All mammals are viviparous and possess diaphragm for breathing.
C. All sponges are marine.
D. All reptiles possess scales, have a three chambered heart and are cold blooded (poikilothermal).
Correct Answer : A.
Platypus is anoviparous mammal. Spongilla and Euspongia are fresh water sponges. crocodiles have four chambered heart. In the members of class chondrichthyes the notochord is persistent throughout life.