If the pair of straight lines x2 - 2pxy - y2 = 0 and x2 - 2qxy - y2 = 0 be such that each pair bisects the angle between the other pair, then
Equation of bisector of both pair of straight lines,
px2 + 2xy - py2 = 0
qx2 + 2xy - qy2 = 0
q/1 = 2/-2p = -q/-1
The correct option is A.