The coefficient of $\frac{1}{x}$ in the expansion of ${(1 + x)^n}{\left( {1 + \frac{1}{x}} \right)^n}$ is
The coefficient of $\frac{1}{x}$ in the expansion of ${(1 + x)^n}{\left( {1 + \frac{1}{x}} \right)^n}$ is
- A
$\frac{{n!}}{{(n - 1)!(n + 1)!}}$
- B
$\frac{{(2n)\,!}}{{(n - 1)!(n + 1)!}}$
- C
$\frac{{n!}}{{(n - 1)!(n + 1)!}}$
- D
None of these
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