A person standing on an open ground hears the sound of a jet aeroplane, coming from north at an angle 60° with ground level. But he finds the aeroplane right vertically above his position. If ‘v’ is the speed of sound, then speed of the plane is

• A. \(\frac{{\sqrt 3 }}{2}\;v\)
• B. v
• C. \(\frac{{2v}}{{\sqrt 3 }}\)
• D. \(\frac{v}{2}\)