ASSERTION: Some animals permit copulation only during oestrous cycles.
REASON: Oestrous cycle is observed in non-primate animals.

A. Both assertion and reason are correct and Reason is the correct explanation for assertion.
B. Both assertion and reason are correct and Reason is not the correct explanation for assertion.
C. Assertion is correct but reason is incorrect
D. Both assertion and reason are incorrect

Hint: The oestrous cycle is the steps of unrelenting physiological changes that are stimulated by reproductive hormones in nearly all mammalian therian females. Estrous cycles begin after sexual maturity in females and are suspended by anestrous phases or by pregnancies. Characteristically, estrous cycles persist until death.

Complete answer:
Among females of placental mammals, there are cyclical alterations in ovaries, accessory reproductive ducts, and hormones throughout the reproductive phase. Such cyclical changes during reproduction are known as oestrous cycles in non-primate mammals like cows, sheep, rats, deer, etc. It is composed of a small period of oestrous or heat followed by an oestrous or passive period. The sex urge is amplified and the female authorizes copulation only during oestrous period.

Placental mammal females exhibit cyclical changes in the actions of ovaries and accessory ducts along with hormones through the reproductive phase. Such cyclical changes for the period of reproduction are known as oestrus cycle among non-primate mammals such as cows, sheep, etc., whereas in primates like a monkey, apes, and humans such cyclical changes are known as the menstrual cycle.

Hence, the correct answer is option (B).

Note: The one breeding season per year includes species, like bears, foxes, and wolves, and classically in spring to allow the growth of the offspring during the warm season to assist survival during the next winter. Rabbits and cats do not include an estrous cycle, instead being induced to ovulate by the act of mating and are able to consider at almost any arbitrary moment. The timing of estrus is synchronized with seasonal accessibility of food and other conditions such as migration, predation, etc and the goal being to amplify the offspring's possibilities of survival.