A particle moves under the effect of a force F = c x from $\mathrm{x}=0\text{ to }\mathrm{x}={\mathrm{x}}_1$  The work done in the process is

• A

  ${\mathrm{cx}}_1^2$

• B

  $\frac{1}{2}{\mathrm{cx}}_1^2$

• C

  ${\mathrm{cx}}_1^3$

• D

  zero