45. Two long parallel wires are a distance 2a apart, as shown. Point P is in the plane of the wires and a distance a from wire X . When there is a current I in wire X and no current in wire Y , the magnitude of the magnetic field at P is Bo. When there are equal currents I in the same direction in both wires, the magnitude of the magnetic field at P is
A) 2Bo/3
B) 10B0/9
C) 4Bo/3
D) 2Bo
