The answer is D: The Medical Information Bureau.
Explanation for each option:
A. The agent's report: This typically contains information gathered by the insurance agent during the application process, such as the applicant's financial status, lifestyle, and other personal details, but not detailed health history.
B. A medical examination: While a medical examination can provide current health information, it does not provide a comprehensive history of the applicant's past health issues.
C. The inspection report: This report usually includes information about the applicant's lifestyle, occupation, and financial status, but not detailed health history.
D. The Medical Information Bureau (MIB): The MIB is a cooperative data exchange formed by insurance companies to share information about individuals' health histories. It helps underwriters verify the accuracy of the information provided by applicants and identify any potential risks based on past health issues.
In summary, the Medical Information Bureau is the most relevant source for an underwriter to obtain information concerning an applicant's health history.