Which of the following organisms exhibits all the following features?

(a) Poikilothermy

(b) Three-chambered heart 

(c External fertilisation 

(d) Indirect development

Bufo is an amphibian and has a three-chambered heart. It exhibits external fertilisation and indirect development.

Clarias, Pristis and Betta are fishes and have a two-chambered heart.

Both fishes and amphibians exhibit poikilothermy (cold-blooded).