For the spontaneity of a reaction,which statement is always true?

$A$ chemical reaction cannot occur at all if

For the reaction $CaCO_{3(s)} \to CaO_{(s)} + CO_{2(g)}$,given $\Delta H^o = 178.3 \, kJ$ and $\Delta S^o = 160 \, J \cdot K^{-1}$. At what temperature will the reaction become spontaneous?

For the conversion of limestone to lime,$CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$,the values of $\Delta H^{\circ}$ and $\Delta S^{\circ}$ at $298 \, K$ and $1 \, bar$ pressure are $+179.1 \, kJ \, mol^{-1}$ and $160.2 \, J \, K^{-1} \, mol^{-1}$ respectively. Assuming $\Delta H^{\circ}$ and $\Delta S^{\circ}$ do not change with temperature,at what temperature (in $K$) will the conversion of limestone to lime become spontaneous (in $, K$)?

What happens during a spontaneous process?

Based on the provided table, which of the following options correctly identifies the spontaneous reactions?

	$\Delta_r H^{\circ}$	$\Delta_r S^{\circ}$	$\Delta_r G^{\circ}$	Spontaneity of the reaction
$A$	$+$	$+$	$+$	Spontaneous at low $T$
$B$	$+$	$+$	$-$	Spontaneous at high $T$
$C$	$-$	$-$	$-$	Spontaneous at low $T$
$D$	$+$	$-$	$+$	Spontaneous at high $T$