A nurse is educating a group of nursing students about the signs of pregnancy. Which of the following is considered a positive sign of pregnancy?

A. Positive urine pregnancy test: A positive urine pregnancy test detects hCG but can be influenced by other conditions like trophoblastic disease. It is classified as a probable sign, not a definitive confirmation of pregnancy. B. Fetal movement felt by the mother: Perception of fetal movement (quickening) is a presumptive sign. It is subjective and can be confused with other sensations, so it is not a reliable indicator of pregnancy. C. Auscultation of fetal heart tones by Doppler: Hearing fetal heart tones is a positive sign of pregnancy. It provides objective evidence of a fetus, confirming the presence of life inside the uterus and ruling out other conditions. D. Breast tenderness and enlargement: These are presumptive signs and can occur due to hormonal changes unrelated to pregnancy. They are common in the premenstrual phase and thus not diagnostic on their own.