The lizards go for winter sleep because A. They are cold-blooded B. They are warm-blooded C. They have the capability of homeostasis D. None of the above
Hint: Reptile are essentially cold-blooded organisms. They're generally conformers, that's why they can't keep their internal heat consistent with the external environment. Lizards belong to the group of reptiles and hibernate during the winter season.
Complete answer: Cold-blooded animals such as reptiles, amphibians, insects, arachnids, and fishes adopt a physiological behavior to tide over difficult weather conditions by hibernating. Hibernation is nothing but a deep sleep that helps animals to save lots of energy and survive the winter without eating much. During hibernation, the animal's blood heat drops, and its heartbeat and its breathing rate decrease drastically in order to prevent them from spending much energy. There's a particular temperature below which their metabolism just won't work. The rationale is that each chemical reaction requires an optimum temperature, and since the temperature is lowered in winters, all the chemical reactions in an organism diminish. So, lizards, in order to cope with the tough climate, hibernate during winters by going into a dormant phase.
So, the correct answer is option A. They are cold-blooded.
Note: Although it may sound as normal sleep, in reality, just entering the winter-sleep requires tons of preparation. This preparation starts months beforehand the arrival of chilly conditions. These animals also have to search for special hibernating spaces to pass the months sleeping.