The toxic substances in the diet are detoxified in human body by

Options

A. Liver
B. Kidney
C. Lungs
D. Stomach

Answer

To solve the question "The toxic substances in the diet are detoxified in the human body by," we need to analyze the functions of the given options: liver, kidney, lungs, and stomach.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the detoxification of toxic substances that enter the body through the diet. Detoxification refers to the process of converting harmful substances into less harmful ones.

2. **Analyzing the Options**:
- **Stomach**: The primary function of the stomach is to churn and mix food with gastric juices, initiating the digestion of proteins and lipids. It does not play a role in detoxifying substances. Therefore, the stomach is not the correct answer.

- **Lungs**: The lungs are involved in gas exchange, taking in oxygen and expelling carbon dioxide. While they help remove carbon dioxide (which is toxic in high concentrations), they do not detoxify dietary substances. Thus, the lungs are also not the correct answer.

- **Kidney**: The kidneys filter blood and excrete waste products, primarily urea, which is formed from ammonia and carbon dioxide in the liver. However, the kidneys do not perform the detoxification process; they are involved in excretion. Therefore, the kidneys are not the correct answer.

- **Liver**: The liver is the primary organ responsible for detoxification in the body. It converts highly toxic substances like ammonia into less toxic substances such as urea through the urea cycle. This process involves several steps and enzymes, and the resulting urea is then transported to the kidneys for excretion. Hence, the liver is the correct answer.

3. **Conclusion**: After analyzing all the options, the correct answer to the question is **liver**.

### Final Answer:
The toxic substances in the diet are detoxified in the human body by the **liver**.