The filtration units of kidneys are called

Options

A. ureter
B. urethra
C. neurons
D. nephrons

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the filtration units of the kidneys.

2. **Role of Kidneys**: Kidneys are vital organs that are primarily responsible for excretion and filtration of waste products from the blood.

3. **Identifying the Options**: The options provided are:
- A) Ureter
- B) Urethra
- C) Neuron
- D) Nephrons

4. **Analyzing Each Option**:
- **Ureter**: This is a tube that connects the kidneys to the bladder. It does not filter blood.
- **Urethra**: This is a tube that carries urine from the bladder to the outside of the body. It does not filter blood.
- **Neuron**: Neurons are the basic units of the nervous system and are involved in transmitting signals, not in filtration.
- **Nephrons**: These are the functional units of the kidneys that perform the filtration of blood to form urine.

5. **Conclusion**: Since nephrons are the structures responsible for filtering blood in the kidneys, the correct answer is D) Nephrons.

**Final Answer**: The filtration units of kidneys are called **nephrons**.

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