Final answer:
Option (b), The normal appearance of amniotic fluid is clear and watery, but it can become greenish or yellowish if meconium is present, which is usually detected at childbirth.
Step-by-step explanation:
The normal appearance of amniotic fluid is clear and watery. This fluid is essential for the protection and nourishment of the growing fetus inside the amniotic sac. While normal amniotic fluid is clear, the presence of meconium, which is the infant's first feces, can cause the fluid to have a greenish or yellowish tinge.
Meconium in the amniotic fluid is often not detected until childbirth when the amniotic sac ruptures. It is important for healthcare professionals to manage meconium-stained amniotic fluid properly to prevent complications in the newborn.