Three Long,straight,parallel Wires Each Carry a Current of 10 a in the Positive

Multiple Choice

Three long,straight,parallel wires each carry a current of 10 A in the positive x direction.If the distance between each wire and the other two is 10 cm,what is the magnitude of the magnetic force on a 20-cm length of either of the wires?

A) 57 $\mu$ N
B) 40 $\mu$ N
C) 69 $\mu$ N
D) 50 $\mu$ N
E) 20 $\mu$ N