What signs may indicate Stan is experiencing activity intolerance?

The indication that Stan is experiencing activity intolerance is best represented by the signs of being diaphoretic and reporting feelings of being "shaky." Diaphoresis, or excessive sweating, can occur as a physiological response to increased stress during activity, which includes the body’s attempt to cool down when it is experiencing distress. This symptom, coupled with feelings of shakiness, suggests that Stan's body is struggling to cope with the demands being placed on it, which is characteristic of activity intolerance.

When an individual is unable to perform activities without undue fatigue or discomfort, these physical signs can be clear indicators. The feelings of shakiness may point to an inadequate supply of oxygen to the muscles or issues with blood glucose levels, both of which signify that the body is unable to maintain normal functionality during exertion.

The other options present signs that do not align with activity intolerance. For instance, pale skin with stable vital signs may not directly indicate activity intolerance but could suggest other issues. Confident movements without discomfort would typically signify that an individual is coping well with activity, and normal respiratory rate and depth often reflect adequate physiological functioning. Thus, option B accurately identifies the specific signs associated with difficulty in tolerating activity.