Crude petroleum can be purify by

Options

A. separation cone
B. fractional distillation
C. distillation
D. All of these

Explanation

### Step-by-Step Solution:

1. **Understanding Crude Petroleum**: Crude petroleum is a natural, unrefined petroleum product composed of hydrocarbon deposits and other organic materials. It needs to be purified to obtain useful products like gasoline, diesel, and other petrochemicals.

2. **Identifying the Purification Process**: The primary method used to purify crude petroleum is **fractional distillation**. This process separates the crude oil into its various components based on their boiling points.

3. **Process of Fractional Distillation**:
- **Heating**: Crude oil is heated in a distillation column. The heat causes the crude oil to evaporate.
- **Vapor Rising**: The vapors rise through the column, which is cooler at the top. As the vapors move up, they start to cool down.
- **Condensation**: Different hydrocarbons condense back into liquid at different heights in the column, depending on their boiling points. Heavier fractions condense lower down, while lighter fractions condense higher up.
- **Collection**: The separated components are collected at various levels of the column, allowing for the extraction of different products.

4. **Conclusion**: The correct answer to the question "Crude petroleum can be purified by" is **fractional distillation**.