1.there are five pairs ______ ,but i am at a loss which to b

1.there are five pairs ______ ,but i am at a loss which to buy.
A to be chosen B to choose from C for choosing
我知道为什么选B 但我想知道不能选AC的原因
2.what surprised me was not what he said but ______ he said it.
Athe way Bin the way that C in the way
我也懂得选A 但我想听听怎么解释不能选BC