The passage distinguishes between short-term and chronic stress. While short-term stress may increase alertness, chronic stress is associated with negative health effects. One of the effects specifically mentioned is increased blood pressure. Option C is therefore correct. Options A and D describe benefits not associated with chronic stress in the passage. Option B is incorrect because the passage states that chronic stress weakens, rather than strengthens, the immune system. The NEX exam often includes questions that test the ability to identify contrasting ideas within a passage, such as short-term versus long-term effects.

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