Final answer:
The correct answer is c) Anxiety causes a decline in performance or mood. This is based on the description in the text of how stress can initially boost performance but becomes detrimental once it surpasses an optimal level, leading to distress and decreased performance.
Step-by-step explanation:
The impact of anxiety on performance and mood is described in the provided text. According to the text, as stress levels increase, there is an initial improvement in performance and general well-being, called eustress. When stress reaches an optimal level, performance is at its peak, characterized by high energy, focus, and efficiency. However, past this optimal point, excessive stress leads to distress, which is detrimental. Individuals experiencing distress feel overwhelmed, fatigued, and their performance declines, exemplifying this effect with severe test anxiety that impairs concentration and negatively affects test performance.
From the options provided, the correct statement describing the impact of anxiety in the provided text is c) Anxiety causes a decline in performance or mood. This reflects the negative consequences of excessive stress levels as described in the text, where a person's performance begins to suffer, and health may start to erode.