Which is present in the kidney ?

Options

A. Glomerulus
B. Ciliated nephrons
C. Middle kidneys duct
D. Nephridia

Answer

### Step-by-Step Solution:

1. **Identify the Options**: The question provides several options: glomerulus, ciliated nephrons, middle kidneys, duct, and nephredia.

2. **Understand the Structure of the Kidney**: The kidney is made up of functional units called nephrons. Each nephron consists of a renal corpuscle and a renal tubule.

3. **Focus on the Nephron**: The renal corpuscle, also known as the Malpighian body, contains two main structures: Bowman's capsule and the glomerulus.

4. **Define the Glomerulus**: The glomerulus is a network of capillaries located within Bowman's capsule. It plays a crucial role in the filtration of blood to form urine.

5. **Evaluate the Other Options**:
- **Ciliated Nephrons**: Nephrons are not ciliated; they do not have cilia.
- **Middle Kidneys**: This term does not refer to a specific structure in the kidney.
- **Duct**: While ducts are present in the kidney, they are not the primary functional unit.
- **Nephredia**: This term refers to excretory structures in some invertebrates, not in the human kidney.

6. **Conclusion**: Based on the above analysis, the correct answer is glomerulus, as it is the only structure listed that is present in the kidney.

### Final Answer:
The correct option is **glomerulus**.

---