Which of the following is a physical sign of stress?

Frequent headaches are often recognized as a physical sign of stress due to the body's physiological response to stressors. When an individual experiences stress, the body enters a state of heightened awareness, which can lead to muscle tension, particularly in the neck and shoulders. This tension can result in tension headaches or exacerbate existing headache conditions.

In contrast, increased motivation, enhanced problem-solving skills, and heightened memory abilities are typically not direct physical signs of stress. While some individuals may experience temporary increased focus or productivity under mild stress, these are more psychological responses rather than physical manifestations. Thus, frequent headaches serve as a clear indicator of the body's physical reaction to stress.