Assertion . Mast cells in human body release excessive amount of inflammatory chemicals which cause allergic reactions.
Reason . Allergens in the environment on reaching human body stimulates mast cells in certain individuals

Options

A. If the both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true and the reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false statements.

Explanation

To analyze the assertion and reason provided in the question, we will break down each statement and evaluate their validity step by step.

### Step 1: Analyze the Assertion
**Assertion**: Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions.

- **Explanation**: Mast cells are a type of white blood cell that play a crucial role in the immune response. When they encounter allergens (substances that can cause an allergic reaction), they release inflammatory chemicals such as histamine and serotonin. These chemicals lead to various symptoms associated with allergies, such as itching, swelling, and redness. Therefore, the assertion is **true**.

### Step 2: Analyze the Reason
**Reason**: Allergens in the environment, upon reaching the human body, stimulate mast cells in certain individuals.

- **Explanation**: Allergens can include a variety of substances such as pollen, dust mites, pet dander, and certain foods. When these allergens enter the body, they can trigger the immune system in individuals who are sensitive to them. This stimulation leads to the activation of mast cells, which then release the inflammatory chemicals mentioned in the assertion. This statement is also **true**.

### Step 3: Determine the Relationship
Now, we need to determine if the reason correctly explains the assertion.

- The assertion states that mast cells release inflammatory chemicals causing allergic reactions. The reason explains that this occurs when allergens stimulate mast cells in certain individuals. Since the reason provides a valid explanation for the assertion, we conclude that both statements are true and the reason supports the assertion.

### Conclusion
Both the assertion and the reason are true, and the reason accurately explains the assertion. Therefore, the correct answer is that both statements are true, and the reason is a correct explanation of the assertion.

### Final Answer
Both the assertion and reason are true, with the reason being a correct explanation of the assertion.

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