Combine is an implement used for

Options

A. threshing
B. harvesting
C. winnowing
D. both (a) and (b)

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Combine**: A combine is an agricultural implement used primarily in crop production. It is a machine that performs multiple tasks in the field.

2. **Functions of a Combine**: The main functions of a combine include:
- **Harvesting**: This is the process of cutting and gathering mature crops from the fields.
- **Threshing**: This involves separating the edible part of the crop from the chaff or husk after harvesting.

3. **Mechanics of the Combine**: The combine operates mechanically, meaning it uses machinery to perform these tasks efficiently and quickly compared to manual labor.

4. **Clarifying Other Processes**: It is important to note that while winnowing is another agricultural process, it is not performed by a combine. Winnowing is the process of separating the lighter chaff from the heavier grains, typically done after threshing.

5. **Conclusion**: Therefore, the combine is specifically used for harvesting and threshing crops, making it a crucial tool in modern agriculture.