Given locus is (−1,1) and equation of directrix is 4x+3y−24=0 The equation of axis which perpendicular to directrix is 3x−4y+c=0 Point (−1,1)lies on above equation,3(−1)−4(1)+c=0 ⇒−3−4+c=0 ⇒c−7=0 ⇒c=7 Then, equation of axis is3x−4y+7=0 Since. vertex lie on given axis Therefore, only option (d) satisfy the above equation Hence, vertex will be (1,