This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intra Uterine Growth Restriction, Intrapaum and Antepaum Fetal Surviellance, Subject name: Gynaecology & Obstetrics
[{'content': 'Late decelerations are due to : \nSelect and explain. \nA. Uteroplacental insufficiency, B. Cord compression, C. Head compression, D. Fetal Anemia ( Rh Incompatibility )', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Early decelerations are due to head compression (stimulation of vagus nerve) Late decelerations are due to uteroplacental insufficiency (fetal distress/hypoxia) Variable decelerations are due to cord compression (oligohydramnios in labor)', 'role': 'assistant'}]