A block of mass `m` is placed inside a smooth hollow cylinder of radius `R` kept horizontally. Initially system was at rest. Now cylinder is given constant acceleration `2 g` in the horizontal direction by external agent. Find the maximum angular displacement of the block with the vertical.
.
A. `2 tan^(-1)(2)`
B. `tan^(-1)(2)`
C. `tan^(-1)(1)`
D. `tan^(-1)((1)/(2))`
