Which Statement Accurately Describes Travel to Oregon or California on the Overland

Which statement accurately describes travel to Oregon or California on the overland trails during the 1840s?

A) The route was well mapped out and well surveyed.
B) By this period the route detoured around any formidable barriers.
C) Indian massacres wiped out a high percentage of all emigrants.
D) Emigrant families traveled alone in single wagons so that they would not be slowed by the needs of other families.
E) Emigrants cooperated closely with each other and traveled in huge wagon trains.