Final answer:
The correct answer is c. Spleen and lungs.
Step-by-step explanation:
The correct answer is: c. Spleen and lungs.
Endocrine organs are responsible for producing and secreting hormones into the bloodstream. While the liver and kidneys have numerous functions, they are not considered endocrine organs. The pancreas and thyroid both have primary endocrine functions, but they are active throughout life, not just during specific life cycle stages. The heart and stomach also do not have endocrine functions. However, the spleen and lungs do have secondary endocrine functions, meaning they are active only during specific life cycle stages.