Assertion (A): Fever is a symptom for an infection.
Reason (R): Pathogens cannot tolerate high temperature.

Options

A. Both A and R are true and R is the correct explanation for A.
B. Both A and R are true, but R is not the correct explanation for A.
C. A is true and R is false.
D. A is false and R is true.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Assertion (A):** The assertion states that "Fever is a symptom for an infection." This means that when a person has an infection, one of the signs they may exhibit is an elevated body temperature, commonly known as fever.

2. **Understanding the Reason (R):** The reason given is "Pathogens cannot tolerate high temperature." This implies that the increase in body temperature (fever) is a response to the presence of pathogens (disease-causing microorganisms) because they thrive in normal body temperatures.

3. **Linking Assertion and Reason:**
- When pathogens invade the body, the immune system activates and responds by raising the body temperature. This is a defense mechanism aimed at creating an unfavorable environment for the pathogens, as many pathogens cannot survive or reproduce at higher temperatures.
- Therefore, the assertion that fever is a symptom of infection is supported by the reason that pathogens cannot tolerate high temperatures.

4. **Conclusion:** Both the assertion and the reason are correct. The reason provided is a valid explanation for the assertion. Hence, the correct answer is that both the assertion and reason are true, and the reason correctly explains the assertion.

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