The answer is B. Take the Native American's land by force
Step-by-step explanation:
Lewis and Clark were tasked to explore the newly acquired land, and make official claim to it. So A is not the answer. They also took water as far as they could, because they were wanted to find a possible route to trade by. Thus not C. Finally, I think it was Lewis who took detailed noted of things he observed along the way. Thus it is also not D. So it must by B.