The study of the human organ is called physiology. There are different types of organs and these are the heart, kidney, liver and etc.
The correct answer is option D.
According to the question, the fetus is developed from the fertilized zygote and attached to the uterus from the umbilical cord.
All the other options are referring to after the implantation. The fetus has the organs.
Hence, the correct answer is option D.
For more information about the fetus, refer to the link:-
https://brainly.com/question/787658