Sea horse and Flying fish - Cold blooded (poikilotherm)
Pteropus and Ornithorhynchus- Viviparity
Garden lizard and Crocodile - Three chambered heart
Ascaris and Ancylostoma - Metameric segmentation
A. Garden lizard has three-chambered heart and crocodile has a four-chambered heart.
B. Ascaris and Ancylostoma have pseudo segmentation.
C. Sea horse and flying fish are cold-blooded or poikilothermic animals.
D. Pteropus is viviparous and Ornithorhynchus is oviparous.
Hence option C has the correct pair. So, the correct answer is 'Sea horse and Flying fish - Cold blooded (poikilotherm)'.