An infinitely long current carrying wire carries current i. A charge of mass m and charge q is projected with speed v parallel to the direction of current at a distance r from it. Then, the radius of curvature at the point of projection is

• A. \[\frac{2rmv}{q{{\mu }_{0}}i}\]
• B. \[\frac{2\pi rmv}{q{{\mu }_{0}}i}\]
• C.  r
• D. Cannot be determined