Final answer:
Medical warning tags for service members are required for individuals with specific medical conditions that can affect emergency treatment.
Step-by-step explanation:
The requirements for service members to have medical warning tags, commonly known as dog tags, include having a specific medical condition that might require immediate attention in the field, especially in the case of an emergency where the individual cannot communicate their needs. These conditions often include severe allergies (such as to penicillin or bee stings), diabetes, epilepsy, and blood type which is crucial for medical treatment. The tags inform medical personnel about the service member's health status quickly and effectively, potentially saving their life.
Accordingly, the correct answer to the given options would be 1) A specific medical condition.