1. What is the primary role of progesterone in early pregnancy? A. Stimulates uterine contractions B. Promotes mammary gland development C. Maintains the endometrial lining Correct Answer: C Rationale: Progesterone is crucial for maintaining the endometrial lining of the uterus during early pregnancy, which is essential for the implantation and nutrition of the developing embryo. 2. During which trimester does the fetus undergo the most significant anatomical development? A. First trimester B. Second trimester C. Third trimester Correct Answer: A Rationale: The first trimester is critical for fetal development, as this is when the major organs and structures begin to form.