A particle of unit mass is moving along the x–axis under the influence of a force and its total energy is conserved. Four possible forms of the potential energy of the particle are given in Column–I (a and $U_0$ are constant). Match the potential energies in Column–I to the corresponding statement(s) in Column–II.

COLUMN-I		COLUMN-II
A)	$U_1\left(x\right)=\frac{U_0}{2}{[1-{\left(\frac{x}{a}\right)}^2]}^2$	P)	The force acting on the particle is zero at $x = a.$
B)	$U_2\left(x\right)=\frac{U_0}{2}{\left(\frac{x}{a}\right)}^2$	Q)	The force acting on the particle is zero at $x = 0.$
C)	$U_3\left(x\right)=\frac{U_0}{2}{\left(\frac{x}{a}\right)}^2\exp [-{\left(\frac{x}{a}\right)}^2]$	R)	The force acting on the particle is zero at $x = – a.$
D)	$U_4\left(x\right)=\frac{U_0}{2}[\frac{x}{a}-\frac{1}{3}{\left(\frac{x}{a}\right)}^3]$	S)	The particle experiences an attractive force towards x = 0 in the region  $\left|x\right|<a$.
		T)	The particle with total energy $\frac{U_0}{4}$ can oscillate about the point $x = – a.$