This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Most accurate and safe method to diagnose ble pregnancy at 6weeks- 
Select and explain. 
A. Doppler assessment of fetal cardiac activity, B. USG for fetal cardiac activity, C. Urinary Beta-hCG determination, D. Per vaginal examination of uterine size corresponding to 6 weeks gestation
B: USG for fetal cardiac activity
Answer: B: USG for fetal cardiac activity 
Explanation: Answer- B. USG for fetal cardiac activityUSG for fetal cardiac activity:At 6 weeks it is routine to detect fetal cardiac activity by ultrasound5 1/2 Yz to 6 weeks is usually a very good time to detect either a fetal pole or even a fetal hea beat by vaginalultrasound.