Assuming the equation is
y + (y^2 - 5)/(y^2 - 1) = y^2 + y + 2/(y+1),
We check the denominators, which are (y^2 - 1) and (y+1), then we take the least common denominator. Since y^2 - 1 = (y+1)(y-1), this means that the LCD is (y^2 - 1) itself, and this is what we should multiply by. Therefore the best answer is B.