A spherical ball of mass m and radius r rolls without slipping on a rough concave surface of large radius `R=(R= (9)/(7)m)`. It makes small oscillations about the lowest point. Find the time period.

Options

A. `5pi sec`
B. `sqrt(5)pi sec`
C. `(6pi)/(7) sec`
D. `sqrt((7)/(2)) pi sec`

Answer

C