Clinical trials are best described as

• A. Observational surveys without intervention
• B. Experiments that study the effectiveness of medical treatments on actual patients
• C. Studies comparing disease frequencies between groups
• D. Retrospective data collection studies

Answer: (B)

Clinical trials are experiments in which researchers deliberately assign a medical treatment to participants and compare outcomes to a control group to determine effectiveness and safety in real patients. This prospective, interventional design, often with randomization and sometimes blinding, distinguishes trials from observational or retrospective studies that do not assign treatments or rely on past data.