Final answer:
In a fear appeal regarding the use of seat belts, showing the potential for injury is an example of severity, which indicates the level of harm that can occur.
Step-by-step explanation:
In a fear appeal, showing the potential for a devastating injury when seat belts are not used is an example of B) severity. In a fear appeal regarding the use of seat belts, showing the potential for injury is an example of severity, which indicates the level of harm that can occur.
This is because severity in this context refers to the extent of harm or damage that can occur if the advice is not followed, such as the serious injuries one might sustain in a car accident without the protection of a seat belt. By contrast, self-efficacy refers to one's confidence in their ability to take action and is not the correct answer in this scenario.
The other options, cognition and vulnerability, also do not accurately describe showing the potential for devastating injury as a component of a fear appeal.