What document describes an insured's medical history, including diagnoses and treatments?

The Attending Physician's Statement is the correct answer because it is specifically designed to document an insured's medical history in detail, encompassing diagnoses and treatments provided by the attending physician. This statement often plays a critical role in insurance claims and underwriting processes, as it provides the insurer with a comprehensive overview of the patient's medical condition and history.

Other documents listed, such as a Medical Billing Statement, primarily reflect costs associated with medical services and treatments rather than providing an account of the patient's medical history. A Health Insurance Card serves as identification and proof of coverage, while the Patient's Bill of Rights outlines the rights and responsibilities of patients within a healthcare system but does not contain any medical history information. Therefore, the Attending Physician's Statement is the most accurate and relevant choice for describing an insured's complete medical history.