Which term is defined as the process of distinguishing between two conditions?

• A. Evaluation
• B. Differential diagnosis
• C. Prognosis
• D. Radiology

Answer: (B)

Differentiating between two conditions is a diagnostic reasoning process where a clinician considers multiple possible explanations for a patient’s symptoms and uses history, examination, and tests to narrow the list to the most likely diagnosis. The goal is to identify which condition best fits all the clues and, if needed, rule out others with targeted information from tests or further assessment. For example, chest pain can arise from several causes; by evaluating onset, risk factors, associated symptoms, and test results, the clinician narrows the possibilities to the one that fits best.

Other terms don’t describe this specific reasoning step. Evaluation is a broad overall assessment of health, not the focused process of distinguishing between competing diagnoses. Prognosis is about predicting how a disease will progress and its likely outcomes. Radiology refers to imaging methods used to visualize the body, not the diagnostic reasoning process itself.