This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: New Born Infants, Subject name: Pediatrics
[{'content': 'Cardiac looping in a fetus occurs on: \nSelect and explain. \nA. 12-13 days of gestation, B. 16-17 days of gestation, C. 22-24 days of gestation, D. 34-35 days of gestation', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. 22-24 days of gestationThe fetal heart development is a sequential process with paired cardiac tubes evident by 18 days of gestation. The two heart tubes fuse to form the primitive heart tube by day 22 of gestation. Cardiac looping usually starts at days 22-24, as the heart tube bends ventrally and towards the right. With looping of the heart tube, the primitive atria moves upwards and towards the back of the ventricles; the primitive ventricle (future left ventricle) comes to the left while the bulbus cordis (future right ventricle) shifts to the right.', 'role': 'assistant'}]