Which of the following crops was subjected most to continuous selection and domestication by man:

Options

A. Rice
B. Wheat
C. Maize
D. Sugarcane

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which crop has undergone the most continuous selection and domestication by humans. This involves identifying a crop that was originally a wild plant and has been cultivated over generations.

2. **Defining Domestication**: Domestication refers to the process where wild plants are selectively bred over time to enhance desirable traits, making them more suitable for human use. This includes selecting for traits such as yield, nutritional value, and resistance to pests.

3. **Identifying Candidates**: The crops mentioned in the question are maize, rice, wheat, and sugarcane. We need to evaluate which of these crops has the most history of continuous selection and domestication.

4. **Evaluating Each Crop**:
- **Maize**: Originally a wild plant, maize (or corn) has undergone extensive selection and domestication. It was cultivated from wild ancestors in Mesoamerica and has been significantly altered through human intervention.
- **Rice**: While rice has also been domesticated, it was already being cultivated in various regions and has a long history of domestication.
- **Wheat**: Similar to rice, wheat was domesticated early on and has been cultivated for thousands of years.
- **Sugarcane**: Sugarcane has been cultivated for its sweet sap, but it has not undergone the same level of continuous selection as maize.

5. **Conclusion**: Among the options, maize stands out as the crop that has been subjected to the most continuous selection and domestication by humans, transforming from a wild plant into a highly cultivated crop with significant nutritional value.

6. **Final Answer**: The correct answer is **maize**.