Correct Option
Hibernation is a state of metabolic depression in endotherms, characterized by inactivity and a significant reduction in body temperature, heart rate, and metabolic rate. It is a survival strategy adopted by certain animals to conserve energy and endure adverse environmental conditions, particularly during winter when food is scarce and temperatures are low.
Bats are known to hibernate, often in large colonies, to survive cold periods. Bears undergo a prolonged period of winter lethargy or torpor, commonly referred to as hibernation, during which their metabolic rate and body temperature decrease significantly, though generally less dramatically than in smaller true hibernators. Many species of rodents, such as ground squirrels, marmots, and hamsters, are classic examples of animals that undergo deep hibernation.
Therefore, the phenomenon of hibernation can be observed in bats, bears, and rodents.
Incorrect Options
Option (a) is incorrect because while bats and bears do hibernate (or undergo winter torpor), rodents are also well-known hibernators. Excluding them makes this option incomplete.
Option (b) is incorrect as it states that only bears hibernate among the given options. Both bats and various rodent species are established hibernators.
Option (d) is incorrect because, as explained, all three categories of animals listed (bats, bears, and rodents) exhibit the phenomenon of hibernation or a similar state of prolonged torpor.