Two Long Parallel Wires Carry Currents Of $20 \mathrm {~A}$ And $5.0 \mathrm {~A}$

Multiple Choice

Two long parallel wires carry currents of $20 \mathrm {~A}$ and $5.0 \mathrm {~A}$ in opposite directions. The wires are separated by $20 \mathrm {~cm}$ . At what point between the two wires do they produce the same strength magnetic field?

A) $16 \mathrm {~cm}$ from the $20 \mathrm {~A}$ wire
B) $8.0 \mathrm {~cm}$ from the $20 \mathrm {~A}$ wire
C) $18 \mathrm {~cm}$ from the $20 \mathrm {~A}$ wire
D) $12 \mathrm {~cm}$ from the $20 \mathrm {~A}$ wire
E) $4.0 \mathrm {~cm}$ from the $20 \mathrm {~A}$ wire