# Sinks of carbon monoxide $2CO+O_2\qquad \underrightarrow {soil}\qquad x$.$CO+3H_2\qquad\underrightarrow{soil}\qquad y+z$.The $x$ in the equation is

$\begin{array}{1 1}(a)\;CO_2\\(b)\;CO_3\\(c)\;2CO_2\\(d)\;CO\end{array}$

The x in the equation is $2CO_2$
Hence (c) is the correct answer.