# Let $\;P(3 sec \theta , 2 tan \theta)\;$ and $\;Q( 3sec \phi ,2 tan \phi)\;$ where $\;\theta + \phi = \large\frac{\pi}{2}\;$ , be two distinct points on the hyperbola $\;\large\frac{x^{2}}{9} - \large\frac{y^{2}}{16}= 1\;$ . Then the ordinate of the point of intersection of the normals at P and Q is :

$(a)\;\large\frac{11}{3} \qquad(b)\;-\large\frac{11}{3}\qquad(c)\;\large\frac{13}{2}\qquad(d)\;-\large\frac{13}{2}$