Answer:
The sentence that could be added to the passage and maintain its formal style is: "In 1786, Charles designed the plans for the town that would soon bear his name." This sentence provides additional information about Charles's role in the development of the town and is written in a formal style that is appropriate for a historical account. The other sentences are written in a more informal style and contain opinions and emotions that are not relevant to the factual information being presented.
Step-by-step explanation: