Which expedition explored the rocky mountains, the great sand dunes, and the upper rio grande river before being captured by the spanish in 1807?
a.
the sparks expedition
b.
the pike expedition
c.
the long expedition
d.
the bell expedition

Option B

Explanation:

The Pike Expedition is the correct answer.

The Pike Expedition led by army officer Zebulon Pike in 1805. The expedition aimed to search for the source of the Mississippi River and to explore the American southwest.  

He traveled through the present-day Kansas, Nebraska and reached Colorado. A mountain spotted by Pike in the Colorado was named after him. When he entered New Mexico, he along with his men was arrested by Spanish officials and were released near the border of Louisiana territory. His expeditions shed light on Kansas and Colorado and his reports revealed the strength and weaknesses of Spanish in the southwestern territories.