The correct option is B Amniotic fluid
The amniotic fluid is the protective liquid, which is contained by the amniotic sac of the pregnant female.
The amniotic fluid has several roles like it keeps the baby warm, provides lubrication to the growing parts etc.
One important function also includes, that it acts like a liquid shock absorber for the baby by disturbing any force that may push on the mother's uterus.
Thus, the correct answer is option (B).