The point P is the intersection of the straight line joining the points `Q(2,3,5)` and `R(1,-1,4)` with the plane `5x - 4y -z = 1`. If S is the foot of the perpendicular drawn from the point `T(2,1,4)` to QR, then the length of the line segment PS is (A) `1/sqrt2` (B) `sqrt2` (C) ` 2` (D) `2sqrt2`