If the Tributaries of the Mississippi River Were to Erode

Multiple Choice

If the tributaries of the Mississippi River were to erode northeastward and reach Lake Michigan (which happened in the past) ,what would be the effect on the size of the Atlantic Ocean drainage basin shown in the figure below?

A) It would not change.
B) It would become smaller.
C) It would become larger.
D) It is not possible to determine from the information given.