Methyl alcohol is toxic. The reason assigned is:

Options

A. It stops respiratory track
B. It reacts with nitrogen and forms `CN^(-)` in the lungs
C. It increases `CO_(2)` content in the blood
D. It is a reduction product of formaldehyde

Answer

### Step-by-Step Solution:

1. **Understanding Methyl Alcohol**: Methyl alcohol, also known as methanol, is a type of alcohol that is known to be toxic to humans. It is important to recognize its harmful effects.

2. **Toxicity Mechanism**: The toxicity of methanol is primarily due to its metabolism in the body. When ingested, methanol is converted into formaldehyde and then to formic acid, both of which are highly toxic compounds.

3. **Respiratory Effects**: One of the reasons methanol is considered toxic is that it can affect the respiratory system. Methanol can lead to respiratory tract irritation and can cause symptoms such as coughing and difficulty breathing.

4. **Formation of Toxic Byproducts**: Methanol can react with nitrogen in the body to form cyanide ions (CN⁻), which are extremely toxic and can lead to severe health issues, including respiratory failure.

5. **Increase in CO2 Levels**: Methanol metabolism can also lead to an increase in carbon dioxide (CO2) levels in the blood, which can result in metabolic acidosis and further respiratory distress.

6. **Blindness**: In addition to respiratory issues, methanol poisoning can lead to blindness due to the formation of formaldehyde and formic acid, which can damage the optic nerve.

7. **Conclusion**: The main reason assigned to the toxicity of methyl alcohol is its effect on the respiratory tract and the formation of toxic byproducts during its metabolism. Therefore, the correct answer is that it affects the respiratory tract.