Magnetic field strength at the centre of regular pentagon made of a conducting wire of uniform cross section area as shown in figure is:
A. `(5mu_(0)i)/(4pia)[2sin"(72^(@))/(2)]`
B. 0
C. Not zero if current `i` leaves `D` point instead of `E`
D. Zero even if the current `i` leaves point `D` instead of point `E`.
