Which of the following statements are incorrect?
(i). Secondary growth usually occurs in monocotyledons.
(ii). Bark refers to all tissues interior to vascular cambium.
(iii). Lenticels permit the exchange of gases between the outer atmosphere and the internal tissue of the stem.
(iv). Annual rings give an estimate of the age of the tree.

Options

A. a) (i) and (ii) only
B. b) (i) and (iii) only
C. c) (i) and (iv) only
D. d) (ii) and (iv) only

Explanation

To determine which statements are incorrect, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze Statement (i)**:
- The statement claims that "Secondary growth usually occurs in monocotyledons."
- **Explanation**: Secondary growth, which refers to the increase in girth of the plant, is primarily associated with dicotyledons due to the presence of vascular cambium. Monocots typically do not have a vascular cambium, and therefore, secondary growth is rare or absent in them.
- **Conclusion**: This statement is **incorrect**.

2. **Analyze Statement (ii)**:
- The statement claims that "Bark refers to all tissues interior to vascular cambium."
- **Explanation**: In fact, bark refers to all tissues that are exterior to the vascular cambium, including the cork and the secondary phloem. The tissues interior to the vascular cambium are primarily the xylem.
- **Conclusion**: This statement is **incorrect**.

3. **Analyze Statement (iii)**:
- The statement claims that "Lenticels permit the exchange of gases between the outer atmosphere and the internal tissue of the stem."
- **Explanation**: Lenticels are indeed specialized structures that allow for gas exchange between the atmosphere and the internal tissues of the stem. They are essential for respiration in woody plants.
- **Conclusion**: This statement is **correct**.

4. **Analyze Statement (iv)**:
- The statement claims that "Annual rings give an estimate of the age of the tree."
- **Explanation**: Annual rings, formed by the growth of xylem in a tree, can indeed be counted to estimate the age of the tree. Each ring typically represents one year of growth.
- **Conclusion**: This statement is **correct**.

### Final Conclusion:
Based on the analysis, the incorrect statements are:
- Statement (i): Secondary growth usually occurs in monocotyledons.
- Statement (ii): Bark refers to all tissues interior to vascular cambium.

Thus, the answer is that statements **(i) and (ii)** are incorrect.