The correct answer is A) they were primary - source entries that recorded an authentic view of uncharted America.
President Thomas Jefferson commissioned Lewis and Clark to explore uncharted territory to provide the U.S government with information about the lands west of Mississippi. Their journal entries were so valuable in that they were primary - source entries that recorded an authentic view of uncharted America.
President Jefferson asked Congress for $2,500 to finance exploration of the unknown Pacific West of the United States. So in 1804, William Clark and Meriwether Lewis, successfully traveled the Missouri River to cross the Rocky Mountains, the Columbia River and reached the Pacific Ocean on November 1805.