If \[{{x}^{m}}\]occurs in the expansion of \[{{(x+1/{{x}^{2}})}^{2n}}\], then the coefficient of \[{{x}^{m}}\]is

• A. \[\frac{(2n)!}{(m)!(2n-m)!}\]      
• B. \[\frac{(2n)!3!3!}{(2n-m)!}\]
• C. \[\frac{(2n)!}{\left( \frac{2n-m}{3} \right)!\left( \frac{4n+m}{3} \right)!}\]
• D. none of these