If B is 130 degrees the other angles must add up to 50 degrees (180-130). The only answers that fit are A and C because the other angles are too large. If angle C is 12.5 degrees then angle A must be 37.5 degrees; or vice versa; if 25 then A is also 25 and the triangle is isosceles. If there is only one answer then it must be 25 because we wouldn't otherwise know whether it was A or C. Because the angles are the same then they must both be 25 degrees, and there's no need to distinguish between A and C.