Which organs are part of both the reproductive and endocrine systems?

The ovaries and testicles are integral to both the reproductive and endocrine systems, which is why this answer is correct. The ovaries are the female reproductive organs that produce eggs and also secrete hormones such as estrogen and progesterone, playing a vital role in regulating the menstrual cycle and maintaining pregnancy. Similarly, testicles are the male reproductive organs responsible for producing sperm and secreting hormones like testosterone, which is crucial for male development, reproductive function, and overall health.

In contrast, the other options consist of organs that do not serve both functions. The heart and lungs are primarily involved in the circulatory and respiratory systems, respectively. The liver and kidneys play key roles in metabolism and waste removal rather than reproductive or hormonal functions. The brain and spinal cord are central components of the nervous system and, while they can influence endocrine activities, do not directly partake in reproductive functions. Thus, the unique dual roles of the ovaries and testicles make them distinct members of both systems.