$\text{ If the term free from }x\text{ is the expansion of }{\left(\sqrt{x}-\frac{k}{x^2}\right)}^{10}\text{ is }405,\text{ then the value of }\mathrm{k}\text{ . }$

• A

  $\pm 3$

• B

  $\pm 2$

• C

  $\pm 1$

• D

  $\pm 5$