Which of the following is NOT an effect included in the "stress cocktail" response?

The correct answer highlights a key aspect of the body's physiological response to stress, often referred to as the "stress cocktail." When an individual experiences stress, the body prepares to respond to perceived threats through a series of biological changes. These changes include increased blood flow to the limbs, heightened heart rate, and enhanced clotting speed in case of injury—all of which are designed to equip the body to deal with challenges effectively.

However, decreased muscle tension is not consistent with the physiological effects of stress. In fact, during stressful situations, muscle tension typically increases as a part of the preparation for action, known as the fight-or-flight response. The heightened state of readiness involves tightening of the muscles, which prepares the body for quick responses, whether to fight the threat or flee from it. Thus, decreased muscle tension does not align with the other responses indicative of the "stress cocktail," making it the exception among the effects listed.