The correct option is A y=0
We know equation of normal to the hyperbola x2a2−y2b2=1 is given by, a2xx1+b2yy1=a2−b2
Thus, required normal is, 5x+16y0=9
Clearly denominator of second term of L.H.S is 0 so the equation of line is, y=0
Hence, option 'A' is correct.