Which theory upturned the humoral theory of illness in the modern era?

The question asks which theory "upturned" (overturned or replaced) the humoral theory of illness in the modern era. The humoral theory was an ancient medical concept that proposed that illness was caused by an imbalance of four bodily fluids (humors). This theory dominated Western medicine for centuries. In the modern era, scientific advancements led to new understandings of disease. Cellular Pathology, primarily developed by Rudolf Virchow in the 19th century, established that diseases originate at the cellular level. This theory revolutionized medicine by shifting the focus from imbalances of humors to specific changes and dysfunctions within cells and tissues. It provided a concrete, observable basis for disease, fundamentally replacing the abstract humoral theory. Let's consider the other options: a. Disease automation: This is not a recognized medical theory that replaced the humoral theory. b. Behavioural analysis: This is a field of psychology focused on understanding behavior, not a theory of illness that replaced the humoral theory. d. Functional theory: This term is too general and does not refer to a specific medical theory that replaced the humoral theory. Therefore, Cellular Pathology is the theory that replaced the humoral theory of illness. The correct option is: c. Cellular Pathology