Drugs That Lead to Birth Defects in the Formation of the Limbs

Drugs that lead to birth defects in the formation of the limbs are most damaging when the conceptus is exposed to them during weeks

A) 1-2 of development, before the placenta is fully formed.
B) 4-8 of development, when limbs are undergoing peak development.
C) 12-16 of development, when limbs have formed but are not fully mature.
D) 24-28 of development, when plasticity of surrounding tissues has been lost.