This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnosis of Pregnancy, Subject name: Gynaecology & Obstetrics
[{'content': 'Which of the following serves as the MOST DIAGNOSTIC sign of Pregnancy? \nSelect and explain. \nA. Amenorrhoea, B. Quickening, C. Foetal heart sounds, D. Distention of abdomen', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. C. Foetal heart soundsPresence of fetal heart sounds is considered to be one of the most diagnostic signs of pregnancy.Other absolute signs of pregnancy are mentioned as follows:* Perception of active fetal movements and Palpation of fetal parts.* Ultrasonographic evidence of gestational sac and embryo in early pregnancy and even later.Probable signs:* Osiander's sign (increased pulsation felt through lateral fornix by 8 weeks), Chadwick's sign (Blue hue of vagina), and Goodell sign (softening of cervix)* Enlargement of the abdomen.* Change in shape, size as well as consistency of uterus* Softening of cervix* Internal as well as external ballottement* Contraction of Braxton Hicks", 'role': 'assistant'}]