The amorphous form of silica is

$FeS_2$ is

The three elements $X$,$Y$ and $Z$ with electronic configurations shown below all form hydrides:

Element	Electronic configuration
$X$	$1s^2, 2s^2, 2p^2$
$Y$	$1s^2, 2s^2, 2p^6, 3s^1$
$Z$	$1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 3d^{10}, 4s^2, 4p^5$

Which set of properties match correctly with properties of the hydrides of these elements?

Match the following:

List-$I$ (Compound)	List-$II$ (Silicate)
$A$. Zircon $(ZrSiO_4)$	$P$. Ring/Cyclic
$B$. Talc $(Mg_3(OH)_2(Si_2O_5)_2)$	$Q$. Ortho
$C$. Thortveitite $(Sc_2Si_2O_7)$	$R$. Pyro
$D$. Benitoite $(BaTiSi_3O_9)$	$S$. Sheet

Assertion: Diamond is a bad conductor.
Reason: Graphite is a good conductor.

Which of the following compounds is the most volatile among $CH_4, SiH_4, GeH_4, SnH_4$?