The correct answers are A) Father Marquette Jaques and D) Louis Jolie.
The explores that determined that the Mississippi was not the desired watergate across America were Father Marquette Jaques and Louis Jolie.
Marquette Jaques (1637-1675) was a French explorer and missionary. He was the first explorer form Europe to map the northern side of the Mississippi River. He was a Jesuit and its dedication to exploration made him join Louis Jaques –a trader of fur- to sail and map that part of the Mississippi River. They used two canoes to make the trip and these explorers determined that the Mississippi was not the desired watergate across America.