The correct answer to this open question is the following.
Unfortunately, you forgot to attach the options to answer the question. You did not include the statements, options, words, to chose from the "two" that you mention in your question.
However, trying to help you, we can comment on the following.
US President Thomas Jefferson sent the Corps of Discovery to support Merriwether Lewis and William Clark during the Lewis and Clark Expedition after the Lousiana Purchase.
These corps were military men, a unit of the American Army, well-trained and ready t act in case it was necessary to protect the expedition.
President Jefferson wanted the expedition to explore the newly acquired territories to know more about them and the possibility to be settled by the American people.