Which two of the following sentences from the article include central ideas of the article? 1. The land that makes up the present-day state of Louisiana was only one small part of it.
2. Soon after the purchase, President Thomas Jefferson sent Meriwether Lewis on a westward expedition to explore the nation's vast new lands.
3. The expedition often had to depend on the generosity of Native Americans for their survival, and felt the hard-bargaining Chinookans were taking advantage of them.
4. He threatened to burn down a village in response to another theft, and told his men to kill three Chinooks who tried to steal his dog, Seaman.
(A) 1 and 2
(B) 2 and 3
(C) 3 and 4
(D) 4 and 1