A bead of mass m is attached to one end of a spring of natural length R and spring constant `K=((sqrt(3)+1)mg)/(R )`. The other end of the spring is fixed at a point A on a smooth vertical ring of radius R as shown in fig. The normal reaction at B just after it is released to move is
A. `(mg)/(2)`
B. `sqrt(3) mg`
C. `3 sqrt(3) mg`
D. `(3 sqrt(3) mg)/(2)`
