Why did Jefferson organize the Lewis and Clark expedition of the Louisiana Purchase territory?

Question

A.
Jefferson wanted Lewis and Clark to take a census of inhabitants for determining congressional representation and for tax-collecting purposes.

B.
Jefferson wanted to build a settlement on the Pacific Coast and needed scouts to discover the best site for a new American city.

C.
Jefferson wanted to sign treaties with all of the various tribes of Native Americans who lived west of the Mississippi before they created anti-government alliances.

D.
Jefferson wanted to educate himself and the nation about the natural landscape and people who lived between the Mississippi and the Pacific Coast.

I think its D. Can someone confirm.