Allergy is due to release of chemical like A and B and use of C and D quickly reduce the symptoms of allergy.

Options

A. A-Histamin, B-Adrenalline, C-Serotonine, D- Steroid
B. A-Serotonine, B- Steroid, C- Histamin, D- Adrenaline
C. A-Histamin, B- Serotonin, C-Adrenaline, D- Steroid
D. A-Histamin, B-Steroid, C-Adrenaline, D- Seratonine

Answer

### Step-by-Step Text Solution:

1. **Understanding Allergy**:
- An allergy is defined as an exaggerated immune response to certain antigens, which are known as allergens. Common allergens include dust, pollen, and animal dander.

2. **Identifying Chemicals A and B**:
- The immune response in allergies is primarily mediated by the release of specific chemicals.
- The two key chemicals involved in causing allergy symptoms are **Histamine (A)** and **Serotonin (B)**.
- Histamine is responsible for symptoms such as sneezing, watery eyes, and difficulty breathing.

3. **Identifying Chemicals C and D**:
- To alleviate the symptoms of an allergy, certain medications can be used.
- The two main types of drugs that quickly reduce allergy symptoms are **Antihistamines (C)** and **Steroids (D)**.
- Antihistamines work by blocking the action of histamine, while steroids help reduce inflammation and immune response.

4. **Conclusion**:
- Therefore, the chemicals causing allergy symptoms are Histamine (A) and Serotonin (B), while the medications that help reduce these symptoms are Antihistamines (C) and Steroids (D).

### Summary:
- A = Histamine
- B = Serotonin
- C = Antihistamines
- D = Steroids