The correct option is D Tachyglossus between reptiles and mammals
The living organisms having intermediate characters between two group are called as connecting link. Tachyglossus (spiny and eater) are egg laying mammals. They act as connecting links between reptiles and mammals. Mammalian characters are hair, diaphragm, mammary glands etc., while reptilian characters are large coracoid, being oviparous, laying eggs and having cloaca. Hence, option D is correct.