I cant remember if it is A or C I believe the answer is C
It was the "Oregon Train" that brought settlers to the Willamette Valley, sine although there were other smaller trails in the region, this was the most traveled by those wanting to start new lives and businesses in the region.
Because you need to win the electoral college, instead of the popular vote, a candidate usually tries to campaign in states with lot of electoral votes, and usually refrains from going to smaller states.