Development is the sum of

Options

A. Cell division and cell elongation
B. Cell division and cell differentiation
C. Growth and differentiation
D. Growth and de - differentiation

Answer

**Step-by-Step Solution:**

1. **Understanding Development in Plants:**
- Development in plants refers to the series of processes that a plant undergoes from seed germination to maturity. It includes various stages such as growth, differentiation, and maturation.

2. **Identifying Key Processes:**
- The key processes involved in plant development are:
- **Growth:** This refers to the increase in size and mass of the plant.
- **Differentiation:** This is the process by which cells become specialized to perform specific functions.

3. **Evaluating the Options:**
- The question provides four options:
1. Cell division and cell elongation
2. Cell division and cell differentiation
3. Growth and differentiation
4. Growth and de-differentiation

4. **Analyzing Each Option:**
- **Option 1:** Cell division and cell elongation - While these are important processes, they do not encompass the entirety of development.
- **Option 2:** Cell division and cell differentiation - This option includes differentiation but misses the broader concept of growth.
- **Option 3:** Growth and differentiation - This option captures the essential components of development, as both growth and differentiation are fundamental to a plant's life cycle.
- **Option 4:** Growth and de-differentiation - De-differentiation is not a primary aspect of development and does not fit well with the concept.

5. **Conclusion:**
- The correct answer is **Option 3: Growth and differentiation.** This option accurately represents the sum of processes that define plant development.

---