# If from a point $P(a,b,c)$ perpendiculars $PA,\:PB,\:$ are drawn on $yz\:\:and\:\:zx$ planes. then the equation of the plane $OAB$ is ?
$(a)\:bcx+cay+abz=0\:\qquad\:(b)\:bcx+cay-abz=0\:\qquad\:(c)\:bcx-cay+abz=0\:\qquad\:(d)\:bcx-cay-abz=0$