The correct answer is Option (2) - Gestation period.

The term used to describe the average duration of human pregnancy, which is about 9 months, is the "Gestation period."

Gestation period refers to the length of time between conception (fertilization of the egg by sperm) and birth. In humans, the gestation period typically lasts around 40 weeks or 9 months. During this period, the fertilized egg undergoes various stages of development within the mother's uterus until it reaches a stage where it is ready to be born as a fully developed infant.

Parturition is the process of giving birth, which marks the end of the gestation period.

Ovulation is the release of an egg from the ovary, typically occurring midway through the menstrual cycle.

Implantation refers to the attachment and embedding of the fertilized egg (embryo) into the lining of the uterus, which happens shortly after conception.