उत्तर : 4. "जॉर्ज स्टीफेंसन"
व्याख्या :

The invention of the railway engine is credited to George Stephenson. The correct answer is (D) George Stephenson. George Stephenson, an English engineer, is known for developing the first practical steam locomotive, named "The Rocket," which played a crucial role in the early development of railways.