Answer: Option B
Step-by-step explanation:
The prenatal development of the fetus is very important in order for the fetus to live a healthy life outside the womb.
The vital organs of the fetus must be fully development before delivery of the fetus. The kidney, lungs and brain must be fully developed else the fetus can get exposed to many disease since birth.
The last months of the prenatal development includes the expansion and contraction of valves of heart which undergoes the final maturation.