Final answer:
The subject of this question is Biology. The statement refers to the examination of stool samples and serologic testing.
Step-by-step explanation:
In the context of the given information, the subject of the question is Biology. The statement refers to the examination of stool samples and serologic testing. Stool examination can provide valuable insights into a person's digestive health and can help diagnose various conditions such as infections, malabsorption, and gastrointestinal disorders.