Following are the properties of four minerals P, Q , R and S. Identify them and select the correct option regarding them.
P: It is required for proper functioning of thyroid gland.
Q : It helps in maintaining body's water balance.
R : It is important for haemoglobin formation.
S : It strengthens bones and teeth and helps in blood clotting

Options

A. Deficiency of P causes dryness of eyes and inflammation of tongue.
B. Q is also required for the proper functioning of the nervous system.
C. Deficiency of R causes goitre.
D. S also helps to fight infections and keeps skin and mouth healthy.

Explanation

To solve the question, we need to identify the minerals P, Q, R, and S based on the properties provided and then select the correct option regarding them.

### Step-by-Step Solution:

1. **Identify Mineral P:**
- Property: "It is required for proper functioning of the thyroid gland."
- **Identification:** The mineral that is essential for the thyroid gland's function is **Iodine**.
- **Conclusion:** P = Iodine.

2. **Identify Mineral Q:**
- Property: "It helps in maintaining the body's water balance."
- **Identification:** The mineral that helps maintain water balance in the body is **Sodium**.
- **Conclusion:** Q = Sodium.

3. **Identify Mineral R:**
- Property: "It is important for hemoglobin formation."
- **Identification:** The mineral crucial for hemoglobin formation is **Iron**.
- **Conclusion:** R = Iron.

4. **Identify Mineral S:**
- Property: "It strengthens bones and teeth and helps in blood clotting."
- **Identification:** The mineral that strengthens bones and teeth and is involved in blood clotting is **Calcium**.
- **Conclusion:** S = Calcium.

5. **Select the Correct Option:**
- Now that we have identified the minerals:
- P = Iodine
- Q = Sodium
- R = Iron
- S = Calcium
- We need to analyze the options provided in the question:
1. Deficiency of P causes dryness of eyes and inflammation of the tongue. (Incorrect, this is related to Vitamin B12 deficiency)
2. Q is also required for the proper functioning of the nervous system. (Correct, Sodium is important for nerve function)
3. Deficiency of R causes goiter. (Incorrect, Goiter is caused by iodine deficiency, not iron)
4. S also helps to fight infection and keeps skin and mouth healthy. (Correct, Calcium does have roles in immune function)

- **Conclusion:** The correct option is **Option 2**.