Answer:
b) tanA
Explanation:
The tangent is the opposite side to the angle over the side next to it.
In the case of angle B, the tangent would be the opposite side, AC, over the adjacent side, BC.
tanB = opposite/adjacent = AC/BC
The reciprocal of this would be BC/AC (this is just the fraction flipped around)
The only one that equals this would be tanA since the opposite/adjacent of that one is BC/AC.