Topic: Sentence (বাক্য),

Best Answer Explained in Below-:

The correct option is D: "What was the famous engineer's invention?" because it directly pertains to the key achievements of George Stephenson in the context of the provided information. The passage highlights his role as an outstanding English engineer and inventor, specifically noting his connection to the development of the first railway in Great Britain. It emphasizes his innovation in engineering by mentioning his creation of a new engine for steam locomotives and the transition from wooden rails to metal ones.

This inquiry into his inventions encapsulates the essence of his contributions to railway technology. By asking about his inventions, the question prompts a discussion on the significance of his work, which revolutionized transportation and laid the foundation for modern rail systems. The other options do not directly relate to his engineering accomplishments or contributions, making option D the most relevant to understanding Stephenson's impact as an inventor. Thus, it is a precise and insightful inquiry aligned with the content of the passage.