Which of the following is the most reliable sign for the diagnosis of pregnancy?

Correct option is B

Explanation: A positive urine pregnancy test is the most reliable among the given options because it detects human chorionic gonadotropin (hCG), a hormone produced during pregnancy.
Information Booster: • Amenorrhea is often the earliest sign of pregnancy. • hCG can be detected in urine shortly after conception.
Additional Knowledge: • Nausea, vomiting, and breast tenderness are presumptive signs of pregnancy. • Ultrasonography confirming a fetal heartbeat is a definitive sign of pregnancy. • Pregnancy tests are highly accurate when performed correctly.