The correct answer is A) the long growing season.
What allowed the Middle Colonies to develop trade and commerce was the long growing season.
The Middle colonies were New York, New Jersey, Pennsylvania, and Delaware. These territories were blessed with fertile soil -ideal for farming- and long growing season to grow crops. Indeed, they were called "the breadbasket of America" for their good crops such as hemp, wheat, and corn. These colonies traded their crops with other colonies and exported them to Europe.
