Given below is the plot of a potential energy function $\mathrm{U}\left(\mathrm{x}\right)$ for a system, in which a particle is in one dimensional motion, while a conservative force $\mathrm{F}\left(\mathrm{x}\right)$ acts on it. Suppose that ${\mathrm{E}}_{\text{mech }}=8 \mathrm{J}$, the incorrect statement for this system is :

• A

  at $\mathrm{x}>{\mathrm{x}}_4, \mathrm{K}.\mathrm{E}$. is constant throughout the region.
• Correct answer
  B

  at $\mathrm{x}<{\mathrm{x}}_1, \mathrm{K}.\mathrm{E}$. is smallest and the particle is moving at the slowest speed.
• C

  at $\mathrm{x}={\mathrm{x}}_2, \mathrm{K}.\mathrm{E}$. is greatest and the particle is moving at the fastest speed.
• D

  at $\mathrm{x}={\mathrm{x}}_3, \mathrm{K}.\mathrm{E}.=4 \mathrm{J}$

Hence, the correct answer is option: 'B'.