The simplest expression for arithmetic growth is
(a) root elongation
(b) increase in girth
(c) both (a) and (b)
(d) none of these

Options

A. root elongation
B. increase in girth
C. both (a) and (b)
D. none of these

Answer

To solve the question, "The simplest expression for arithmetic growth is," we need to analyze the provided options and understand the concept of arithmetic growth.

### Step-by-Step Solution:

1. **Understanding Arithmetic Growth**:
- Arithmetic growth refers to a type of growth where a constant amount is added in each time period. This means that the increase is linear and can be represented as an arithmetic progression.

2. **Analyzing the Options**:
- **Option (a)**: Root elongation.
- Root elongation is a process where roots grow longer over time. This growth can be considered as arithmetic because it occurs at a constant rate.
- **Option (b)**: Increase in girth.
- Increase in girth refers to the thickening of stems or roots. This can also be seen as a form of arithmetic growth since it can occur at a constant rate.
- **Option (c)**: Both (a) and (b).
- Since both root elongation and increase in girth can be expressions of arithmetic growth, this option suggests that both are correct.
- **Option (d)**: None of these.
- This option implies that neither (a) nor (b) is correct, which we have already established is not the case.

3. **Conclusion**:
- Since both root elongation and increase in girth can be expressions of arithmetic growth, the simplest expression for arithmetic growth is best represented by **Option (c) both (a) and (b)**.

### Final Answer:
(c) both (a) and (b)

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