Confusing Words - 2

Direction: The question has two statements. Each statement uses a pair of words marked (A) and (B), one of which will make coherent sense in context of the sentence. For each sentence choose the best fit and select the option that indicates all correct answers.

i. Wheat (A) floor / (B) flour is used for making bread.
ii. The (A) principal / (B) principle of our school is a very learned person.