Plica semilunaris is found in

Options

A. kidney of mammals
B. heart of rabbit
C. eye of mammals
D. eyes of frog.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks where the plica semilunaris is found. It is important to identify the anatomical context of the term.

2. **Identifying the Structure**: The plica semilunaris is a small fold of tissue located in the eye. It is associated with the bulbar conjunctiva.

3. **Location in the Eye**: The plica semilunaris is found on the medial canthus (the inner corner) of the eye. This location is significant as it helps in the eye's functionality.

4. **Function of Plica Semilunaris**: This structure is a vestigial remnant of the nictitating membrane (often referred to as a "third eyelid"). It plays a role in the movement of the eye and helps to maintain moisture on the eye surface by assisting in the drainage of tears.

5. **Identifying the Correct Answer**: Given that the plica semilunaris is specifically found in the eyes of mammals, the correct answer to the question is option number 3 (the eye).

6. **Eliminating Incorrect Options**: The other options (kidney, heart, and eyes of the frog) do not contain the plica semilunaris, confirming that option number 3 is indeed the right choice.

### Final Answer:
Plica semilunaris is found in the eye (Option 3).

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