Your research paper is entitled "Factors Improving Transportation in Sacramento Valley Area." Which sentence in paragraph 2 would be MOST helpful as evidence in your paper? A) By the late 1840's dreams of a transcontinental railroad were debated. B) The transportation by a raft is symbolic of the role of transportation in the evolution of local history. C) But the shorter transcontinental crossing at the Isthmus of Panama by a railroad would occur first in 1855. D) Meanwhile, the connection between San Francisco and Sacramento was improved by an expanding, fast, and efficient steamboat service.