Answer:
A.Heart
Step-by-step explanation:
A fertilization is a process in which a male gamete is sperm meet with a female gamete is an egg in a uterus of female body.After fertilization , it form zygote.
Zygote: It is formed when male gamete combine to female gamete in a fertilization process.
After formation of zygote then the zygote develops into the embryo.
During development of embryo, a cell starts to develop about 17 days after fertilization is heart.. A heart is the first organ which developed first after fertilization. Then other organ develops of an embryo.
Therefore, heart starts to develop about 17 days after fertilization .
Hence, option A is true.
Eye is developed after developing of heart. Therefore, option B is false.
Kidney is not developed about 17 days after fertilization . Hence, option C is false.
Liver is not developed first after fertilization .Therefore, option D is false.