Final answer:
The 26-year-old riding a motorcycle across the country is at the greatest risk for death or injury due to high rates of injury-related deaths from motorcycle accidents.
Step-by-step explanation:
Among the young adults listed, the one at the greatest risk for experiencing death or injury is likely the 26-year-old riding a motorcycle across the country. This assessment is based on data indicating motor vehicle injuries are a leading cause of death in young adults. The Centers for Disease Control and Prevention notes that head and traumatic brain injuries, which can be common in motorcycle accidents, are a major cause of immediate death and disability. While each individual's circumstances can contribute to their risk level, activities such as motorcycle riding inherently carry higher risks due to the lack of protective barriers and the high speeds involved.
Comparatively, while living in an urban housing project or being related to an alcoholic can increase certain risks, these do not have as direct a correlation with death or injury as the act of riding a motorcycle. The professional rodeo rider also faces elevated risks due to the dangerous nature of their sport. However, motorcycle accidents are responsible for a significant percentage of injury-related deaths in the United States, making the motorcycle trip a high-risk activity.