A straight line through the vertex P of a △PQR intersects the side QR at the point S and the circumcircle of the triangle PQR at the point T. If S is not the centre of the circumcircle, then
(a) \(\frac1{PS} + \frac1{ST} < \frac 2{\sqrt{QS \times SR}}\)
(b) \(\frac1{PS} + \frac1{ST} > \frac 2{\sqrt{QS \times SR}}\)
(c) \(\frac1{PS} + \frac1{ST} < \frac 4{QR}\)
(d) \(\frac1{PS} + \frac1{ST} > \frac 4{QR}\)
