The correct answer is D) Boston and Philadelphia.
The two present-day US cities that were instrumental in gaining US independence were Boston & Philadelphia.
During the Revolutionary War, Boston was a strategic city for Americans and also for the British troops. The reason was that Boston was the most important port to exportation or importation of goods. It also was an important navigation and transportation center for war and trade ships. Indeed, Boston is known as the birthplace of the American Revolution. Many important events took place in Boston during the revolution years.
The other instrumental city was Philadelphia. As it is well known, Philadelphia was the largest and most important city of America by the time of the Revolutionary War. Philadelphia hosted the First Continental Congress and the Second Continental Congres, where the Declaration of Independence was signed.
They where all either looking for new land or a new route to India.