Answer: Option A
Explanation:
The fusion of male and female gamete and the formation of embryo is known as fertilization. The embryo is then implanted in the uterus of females.
The whole pregnancy is divided into thee trimesters. The first trimester consists of 3 months and next 6 months is also divided into 2 trimester.
The first trimester is very important for the females as there are maximum chances of miscarriage. The development of brain and spinal cord takes place during the first 3 months of pregnancy and then followed by other organs in the 2 trimester.