Bidder’s canal is found in

Options

A. Testes of frog
B. Kidney of frog
C. Ovary of mammal
D. Kidney of mammal

Explanation

### Step-by-Step Solution:

1. **Understanding Bidder's Canal**: Bidder's canal is a structure that is associated with the reproductive system of certain animals, specifically frogs. It plays a role in the transport of sperm.

2. **Identifying the Location**: The question asks where Bidder's canal is found. The options given are:
- Testis of frog
- Kidney of frog
- Ovary of mammal
- Kidney of mammal

3. **Analyzing the Options**:
- **Testis of Frog**: While sperm formation occurs in the testis, Bidder's canal itself is not located in the testis but is associated with it.
- **Kidney of Frog**: Bidder's canal is indeed found in the kidney region of the frog and communicates with the ureter.
- **Ovary of Mammal**: Bidder's canal is not present in the ovary of mammals.
- **Kidney of Mammal**: Bidder's canal is not found in the kidney of mammals.

4. **Conclusion**: Based on the analysis, Bidder's canal is found in the kidney of the frog, as it serves to transport sperm from the testis to the ureter.

5. **Final Answer**: Therefore, the correct answer is **Kidney of Frog**.