Excess use of herbicides or pesticides has resulted in selection of …………X……… varienties in a much lesser timescale and is a result of ………..Y……….. .
Select the correct option for X and Y.

Options

A. X - resistant , Y - natural selection
B. X - mutant , Y - genetic drift
C. X - resistant , Y - anthropogenic action
D. both (a) and (c )

Answer

To solve the question, we need to identify the correct terms for X and Y based on the context provided. The question states that the excessive use of herbicides or pesticides has led to the selection of certain varieties in a shorter time frame, and we need to determine what these varieties are and the underlying reason for this selection.

### Step-by-Step Solution:

1. **Understanding the Context**:
- The question discusses the impact of excessive herbicide and pesticide use on plant varieties.
- It implies that due to this excessive use, certain varieties have been selected over time.

2. **Identifying X**:
- The varieties that are being selected due to the use of herbicides or pesticides are likely to be those that can withstand or resist these chemicals.
- Therefore, the term that fits in place of X is "resistant". This means that the varieties are resistant to the herbicides or pesticides used.

3. **Identifying Y**:
- The next part of the question asks for the reason behind this selection process.
- The options provided include "natural selection" and "anthropogenic action".
- Given that the selection is a direct result of human actions (the excessive use of herbicides and pesticides), the term that fits in place of Y is "anthropogenic action". This indicates that the changes in the varieties are a result of human influence rather than natural processes.

4. **Final Answer**:
- Therefore, the correct terms to fill in the blanks are:
- X = resistant
- Y = anthropogenic action

### Conclusion:
The complete statement would read: "Excess use of herbicides or pesticides has resulted in the selection of resistant varieties in a much lesser timescale and is a result of anthropogenic action."