A bullet of mass m strikes a pendulum bob of mass M with velocity u. It passes through and emerges out with a velocity u/2 from bob. The length of the pendulum is l. What should be the minimum value of u if the pendulum bob will swing through a complete circle?
A. `(2M)/mxxsqrt(5gl)`
B. `M/(2m)sqrt(5gl)`
C. `(2M)/mxx1/sqrt(5gl)`
D. `M/(2m)xx1/sqrt(5gl)`