The magnetic field strength at a point at a distance $d$ from the centre, on the axial line of a very short bar magnet of magnetic moment $M$, is $B$. The magnetic induction at a distance $2d$ from centre, on equatorial line of magnet of magnetic moment $8M$, will be :

Question

( A ) $\frac{B}{2}$
( B ) $\frac{B}{4}$
( C ) $2B$
( D ) $4B$