Rudolf Diesel was the inventor of the diesel engine. He created this engine in the late 19th century, and it is named after him. The diesel engine is very different from petrol or gasoline engines because it works without a spark. Instead, it uses high pressure to heat the air in the cylinder, which then ignites the fuel automatically.

Rudolf Diesel wanted to make an engine that was more efficient than the steam engines of his time. In 1892, he received a patent for his new engine idea, and by 1897, he had built the first working diesel engine. This engine used **less fuel**, was **stronger**, and could be used in **large machines**.

Today, diesel engines are found in many heavy-duty machines such as:
- Trucks and buses
- Ships and trains
- Generators and construction equipment

Diesel engines are preferred for heavy work because they last longer, give more power, and are more fuel-efficient compared to gasoline engines.

Let’s look at the other options:
- **Paul Muller** discovered DDT, a pesticide.
- **Waldeyer** was a German scientist who coined the term “chromosome.”
- **Faraday** was a great physicist who discovered electromagnetic induction, not the diesel engine.

So, the correct answer is clearly **Rudolf Diesel**. His invention changed industries, making transport and power generation more efficient and reliable.