Answer:
The correct answer is D. The conquistador that discovered the Mississippi River was Hernando De Soto.
Step-by-step explanation:
On May 8, 1541, troops from Hernando de Soto reached the Mississippi River. Therefore, de Soto is the first European to spot this river.
De Soto was very little interested in this discovery because it represented, for him, an obstacle to his mission. He and 400 men had to cross a wide and mighty river, which was constantly patrolled by hostile natives. After almost a month, and after the construction of several rafts, he finally crossed the Mississippi with his people and continued his journey westward through present-day Arkansas, Oklahoma, and Texas.