Final answer:
The correct answer is the History of present illness. It provides insight into when the problem began and what has been done to address it, distinguishing it from other sections of the health history form.
Step-by-step explanation:
The section of the health history form that contains information about when the problem started and what the patient has done to treat it is the History of present illness. This section is crucial for healthcare providers to understand the onset, context, and attempts at treatment of the patient's current health issue. Each part of the health history form serves a specific purpose, such as the Prognosis section which predicts the likely outcome of the disease, the Assessment section where the healthcare provider gives their professional judgment on the issue, and the Management plan which outlines the proposed treatment for the problem.