**Explanation:**

The correct fuel used for running automobiles is diesel, which is represented by option C. Diesel fuel is a type of fuel that is commonly used in diesel engines. It is a petroleum-based fuel that is specifically designed for use in diesel engines.

Here is a detailed explanation of the fuels used for running automobiles:

**1. Wood:**
Wood is not used as a fuel for running automobiles. Wood is primarily used as a fuel for heating and cooking purposes. It is not suitable for use in automobiles because it does not have the necessary properties to power an engine.

**2. Coal:**
Coal is not used as a fuel for running automobiles either. Coal is primarily used in power plants for generating electricity and in industrial processes. It is a solid fuel that is not suitable for use in automobile engines.

**3. Diesel:**
Diesel is the correct answer because it is one of the main fuels used for running automobiles. Diesel fuel is a type of fuel that is specifically designed for use in diesel engines, which are commonly found in trucks, buses, and some cars. Diesel engines are different from gasoline engines in their combustion process and fuel delivery system. Diesel fuel is a petroleum-based fuel that is less volatile than gasoline and has a higher energy density. It is more efficient in terms of fuel consumption, and diesel engines are known for their power and torque.

**4. Charcoal:**
Charcoal is not used as a fuel for running automobiles. It is primarily used for cooking and grilling purposes. Charcoal is a solid fuel made from wood or other organic materials that have undergone a process called pyrolysis. It is not suitable for use in automobile engines as it does not have the necessary properties to power an engine.

In conclusion, the correct fuel used for running automobiles is diesel. Diesel fuel is specifically designed for use in diesel engines, which are commonly found in trucks, buses, and some cars. Diesel fuel is a petroleum-based fuel that is more efficient in terms of fuel consumption and provides power and torque to the engine.

Diesel is more combustible than these fuels,it releases energy rapidly.... Diesel and Petrol also used in the automobiles....so the correct answer is C.