Answer:
Option A, tan (30) = 5/b
Step-by-step explanation:
The tan function has a formula of the opposite/adjacent with respect to the angle of interest. Since we are trying to find tan of the 30 degree angle, we look for the sides opposite and adjacent to it. Side AC is right next to the angle, therefore it is the adjacent side. Side BC is on the far side, therefore it is the opposite side. AB is the hypotenuse, which we don't need for tan right now so we can put it aside.
Since tan = opp/adj, and opp = 5 and adj = b
tan (30) = 5/b, which is option A in your case.
