The potential energy of a particle of mass 'm' situated in a uni-dimensional potential field varies as U(x) = Uo [1 cos ax] where U, and a are constants. The time period of small oscillations of the particle about the mean position:
A. 2π√m/aU0
B. 2π√am/U0
C. 2π√m/a2U0
D. 2π√a²m/U0
