Final answer:
Option b) 'parturition' is not part of fetal circulation. 'Parturition' refers to childbirth, while the umbilical vein and foramen ovale are parts of the fetal circulatory system.
Step-by-step explanation:
The aspect of fetal circulation mentioned in the question refers to the unique circulatory system present in a fetus that facilitates the exchange of oxygen and nutrients while bypassing the non-functional fetal lungs. The umbilical vein carries oxygen-rich blood from the placenta to the fetus, and the foramen ovale is a cardiac opening allowing blood to move from the right atrium to the left atrium, bypassing the lungs. However, parturition is not a part of fetal circulation; it is the process of childbirth and involves the delivery of the baby and placenta from the uterus to the external world.