Correct option: C.$xyz\left( {1 + \frac{a}{x} + \frac{b}{y} + \frac{c}{z}} \right)$
C $C_1(\frac{1}{x}),C_2(\frac{1}{y}),C_3(\frac{1}{z})$
$D=xyz\begin{vmatrix}\frac{a}{x}+1&\frac{b}{y}&\frac{c}{z}\\\frac{a}{x}&\frac{b}{y}+1&\frac{c}{z}\\\frac{a}{x}&\frac{b}{y}&\frac{c}{z}+1\end{vmatrix}$
$\frac{C_{21}(1)}{C_{31}(1)}$
$=xyz\begin{vmatrix}\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1&\frac{b}{y}&\frac{c}{z}\\\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1&\frac{b}{y}+1&\frac{c}{z}\\\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1&\frac{b}{y}&\frac{c}{z}+1\end{vmatrix}$
$=xyz(\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1)\begin{vmatrix}1&\frac{b}{y}&\frac{c}{z}\\1&\frac{b}{y}+1&\frac{c}{z}\\1&\frac{b}{y}&\frac{c}{z}+1\end{vmatrix}$
$ \frac{R_{21}(-1)}{R_{32}(-1)}$
$=xyz(\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1)\begin{vmatrix}1&-1&0\\1&1&-1\\1&\frac{b}{y}&\frac{c}{z}+1\end {vmatrix}$
$=xyz(\frac{a}{x}+\frac{b}{y}+\frac{c}{z}+1).1$