In 1673, explorers discovered which river while traveling the Mississippi?

Here is the question :

IN 1673, EXPLORERS DISCOVERED WHICH RIVER WHILE TRAVELING THE MISSISSIPPI?

Here is the option for the question :

St. Lawrence River
Missouri River
Ohio River
Columbia River

The Answer:

And, the answer for the the question is :

MISSOURI RIVER

Explanation:

[STC0016031]. Father Jacques Marquette and Louis Joliet were the first Europeans to see the Missouri River in the summer of 1673. The Missouri River flows into the Mississippi River. Although the Mississippi is frequently mentioned as one of the world’s longest rivers, that claim actually incorporates the lengths of the Missouri and Ohio rivers. When the two rivers are considered separately, the Missouri is about 100 miles longer than the Mississippi.