Formic acid on heating with concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ at 373 K gives $X$, a colourless substance and $Y$, a good reducing agent. The number of $\sigma$ and $\pi$ bonds in $X, Y$ are respectively

What is $C$ in the given sequence of reactions?

$\mathrm{NH}_2 \mathrm{CONH}_2+2 \mathrm{H}_2 \mathrm{O} \rightarrow[\mathrm{X}] \rightleftharpoons 2 \mathrm{NH}_3+\mathrm{H}_2 \mathrm{O}+[\mathrm{Y}]$

The hybridisation of carbon in $X$ and $Y$ respectively are

In the given reaction sequence sequence, $Z$ is