Denaturated alcohol is:

Options

A. Ethanol + methanol
B. Rectified spirit + methanol + naphthalene
C. Undistilled ethanol
D. Rectified spirit

Explanation

### Step-by-Step Solution:

1. **Definition of Denatured Alcohol**: Denatured alcohol is a form of ethanol that has been mixed with additives to make it undrinkable. This is done to discourage recreational consumption.

2. **Components of Denatured Alcohol**: The typical components of denatured alcohol include:
- **Ethanol**: The primary alcohol that is usually found in alcoholic beverages.
- **Methanol**: A toxic alcohol that is added to make the mixture poisonous.
- **Pyridine**: An organic compound that has a bitter taste and contributes to the foul smell of denatured alcohol.

3. **Purpose of Denaturing**: The main purpose of denaturing alcohol is to prevent it from being consumed as a beverage. The additives not only make it toxic but also impart an unpleasant odor and taste.

4. **Uses of Denatured Alcohol**: Denatured alcohol has several practical applications, such as:
- **Fuel**: It can be used as a fuel for camping stoves.
- **Solvent**: It is commonly used as a solvent in various industrial processes.
- **Cleaning Agent**: It is used in cleaning products, including window cleaners and disinfectants.
- **Paint and Varnish**: It is utilized in the paint and varnish industry.

5. **Summary**: Denatured alcohol is essentially a mixture of ethanol, methanol, and pyridine, designed to be toxic and unpalatable to discourage consumption while serving various industrial and cleaning purposes.