Which one of the following categories of animals, is correctly described with no single exception in it ?
A. All reptiles possess scales, have a three - chambered heart, and are cold blooded ( poikilothermal )
B. All bony fish have four pair of gells and operculum oneach side .
C. All sponges are marrize and have collared cells.
D. All mammals are viviporous and possess diaphragms for breathing.