A sphere of mass `M` and radius `R` is attached by a light of length `1` to a point `P`. The sphere rolls without slipping on a circular track as shown. It is released from the horizontal position. The angular momentum of the system about `P` when the rod becomes vertical is :
.
A. `M sqrt((10)/(7)) gl[l + R]`
B. `M sqrt((10)/(7)) gl[ l + (2)/(5) R]`
C. `M sqrt((10)/(7)) gl [l +(7)/(5) R]`
D. none of the above