The cold air from north western Canada add cooler air which follows through seattle and adds rain to the athmosphere and they blow to the west
I dont understand taht to be honest but if i did i wouldve answered them for you
C, details that help readers visualize the settings better. A wouldn't work because it doesn't help the setting, B doesn't help the setting either and D would only add more confusion so UT would have to be C by process of elimination.