menstrual cycle Questions

Which of the following statements are correct regarding female reproductive cycle?A. In non-primate mammals cyclical changes during reproduction are called oestrus cycle.B. First menstrual cycle begins at puberty and is called menopause.C. Lack of menstruation may be indicative of pregnancy.D. Cyclic menstruation extends between menarche and menopause.Choose the most appropriate answer from the options given below:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:Assertion A: Endometrium is necessary for implantation of blastocyst.Reason R: In the absence of fertilization, the corpus luteum degenerates that causes disintegration of endometrium.In the light of the above statements, choose the correct answer: