Final answer:
The addition of a new rail line has made the northern part of the city more convenient.
Explanation:
Convenient is the correct word to fill in the blank. In the context provided, the addition of a new rail line making the northern part of the city much more convenient implies that it has become easier or more accessible to travel within that area.
Learn more about Vocabulary and grammar here:
https://brainly.com/question/16288206
