Currents of $10 \ A$ and $2 \ A$ are passed through two parallel wires $A$ and $B$ respectively in opposite directions. If the wire $A$ is infinitely long and the length of the wire $B$ is $2 \ m$,the force acting on the conductor $B$,which is situated at a distance of $10 \ cm$ from $A$,will be . . . . . . .

• A
  $4 \pi \times 10^{-7} \ N$
• B
  $5 \times 10^{-5} \ N$
• C
  $8 \pi \times 10^{-7} \ N$
• D
  $8 \times 10^{-5} \ N$