Which external factor can impact a student's performance during testing?

Physical health and injuries are significant external factors that can profoundly impact a student's performance during testing. When a student is not physically well—due to illness, fatigue, or injuries—it can hinder their ability to concentrate, process information, and perform tasks effectively. This internal state affects cognitive functions such as memory, attention span, and overall mental clarity, which are crucial during any testing scenario.

While other factors like the instructor's mood, classroom distractions, and the presence of spectators can also influence a student's performance to some extent, they do not directly affect the student's physical state. Ultimately, there is a direct correlation between physical health and a student's ability to demonstrate their knowledge and skills, making it a critical external factor in testing situations.