Column-I contains terms and Column-II contains definitions. Match them correctly and chooe the right answer.

Column-I	Column-II
A. Parturition	1. Attachment of blastoctyst to endometrium
B. Gestation	2. Release of egg from Graafian follicle
C. Ovulation	3. Delivery of baby from uterus
D. Implantation	4. Duration between pregnancy and birth
E Conception	5. Formation of zygote by fusion of the egg and sperm
	6. Stoppage of ovulation and menstruation

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.