The correct answer is A. From fertilization and to the end of the second week
Step-by-step explanation:
Fetal or embryonic development includes different stages from fertilization to birth. The first stage is the pre-embryonic stage, this occurs after fertilization and lasts the two first weeks of pregnancy, it is called pre-embryonic stage because during this there is no an embryo but the zygote implants and later different processes of cell division occur. Additionally, the pre-embryonic stage is followed by the embryonic stage (week 3 to 8) and finally the fetus stage (week 9 to birth). According to this, if students have correctly learned about fetal development they should choose "from fertilization and to the end of the second week" as the period for the pre-embryonic stage.