In anticipation of receiving a fertilized ovum, the lining of the uterine wall:

• A. produces digestive enzymes to break down the ovum
• B. remains unchanged until after fertilization occurs
• C. thickens and becomes more vascularized to support implantation
• D. thins and sheds to prepare for menstruation

Answer: (C)

Verified step by step guidance

1. Understand the context: The uterine lining, also known as the endometrium, plays a crucial role in supporting a fertilized ovum during early pregnancy. Its preparation is part of the menstrual cycle, specifically during the luteal phase.
2. Recall the hormonal influence: After ovulation, the corpus luteum secretes progesterone, which stimulates the thickening and vascularization of the endometrium. This prepares the uterine lining for potential implantation of a fertilized ovum.
3. Clarify the biological process: The thickened and vascularized endometrium provides nutrients and a supportive environment for the developing embryo. If fertilization does not occur, the endometrium sheds during menstruation.
4. Eliminate incorrect options: The uterine lining does not produce digestive enzymes to break down the ovum, nor does it remain unchanged until after fertilization. It also does not thin and shed in anticipation of receiving a fertilized ovum; shedding occurs only if fertilization does not happen.
5. Conclude the correct answer: The uterine lining thickens and becomes more vascularized to support implantation, which is essential for the early stages of pregnancy.