Read the following statements.
(i) The ozone layer is present in the troposphere.
(ii) Density of air decreases with increasing altitude
(iii) Air is an element that surrounds the Earth and makes it hospitable for living organisms.
(iv) Exosphere is the uppermost layer of the atmosphere.
Which of the given statements are correct?

Options

A. (i) and (ii) only
B. (ii) and (iv) only
C. (i) and (iii) only
D. (iii) and (iv) only

Explanation

To determine which of the given statements are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i)**: "The ozone layer is present in the troposphere."
- The ozone layer is actually located in the stratosphere, not the troposphere. Therefore, this statement is **incorrect**.

2. **Statement (ii)**: "Density of air decreases with increasing altitude."
- As we move higher in the atmosphere, the density of air indeed decreases. This is because the air molecules are more spread out at higher altitudes. Therefore, this statement is **correct**.

3. **Statement (iii)**: "Air is an element that surrounds the Earth and makes it hospitable for living organisms."
- While air does surround the Earth and is essential for life, it is not an element; it is a mixture of various gases. Therefore, this statement is **incorrect**.

4. **Statement (iv)**: "Exosphere is the uppermost layer of the atmosphere."
- The exosphere is indeed the uppermost layer of the atmosphere, where the atmosphere transitions into outer space. Therefore, this statement is **correct**.

### Conclusion:
The correct statements are:
- Statement (ii): "Density of air decreases with increasing altitude." (Correct)
- Statement (iv): "Exosphere is the uppermost layer of the atmosphere." (Correct)

### Final Answer:
The correct statements are **(ii) and (iv)**.

---