Answer: The correct answer is A) Rat.
r- selected species are those, which are capable of producing large number of small offsprings in an unstable environments. These species follow exponential growth rate, does not survive to childhood ( as possess very short life span), and have no parental care.
On the contrary, k selected species are present in a stable environment, have low reproductive rate, long life span, and possess parental care. Whale, Eagle, and Elephant are the example of K- selected species.
Thus, rat is an example of r- selected species.