Ketone bodies are formed in .

Options

A. liver
B. spleen
C. kidney
D. heart

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks where ketone bodies are formed in the body. Ketone bodies are important metabolic products that are produced during certain metabolic states, particularly when glucose is not readily available.

2. **Identifying the Options**: The options provided are:
- a) Liver
- b) Spleen
- c) Kidney
- d) Heart

3. **Analyzing Each Option**:
- **Liver**: The liver is known for its role in various metabolic processes, including gluconeogenesis and ketogenesis. Ketone bodies are specifically formed in the mitochondria of liver cells when there is a lack of glucose, such as during fasting or low-carbohydrate diets. Therefore, this option is correct.

- **Spleen**: The spleen's primary function is to filter blood and remove old or damaged red blood cells. It does not play a role in the formation of ketone bodies. Thus, this option is incorrect.

- **Kidney**: The kidneys are primarily involved in filtering waste products from the blood and regulating fluid balance. They do not produce ketone bodies. Therefore, this option is also incorrect.

- **Heart**: The heart's main function is to pump blood throughout the body. It does not have a role in the production of ketone bodies. Hence, this option is incorrect as well.

4. **Conclusion**: Based on the analysis, the correct answer is the liver, as it is the organ responsible for the formation of ketone bodies.

**Final Answer**: Ketone bodies are formed in the **liver**.

---