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

The maximum work done in expanding $16 \ g$ of oxygen at $300 \ K$ from an initial volume of $5 \ dm^3$ to a final volume of $25 \ dm^3$ isothermally and reversibly is $(\log_{10} 5 = 0.699)$.

For water,the value of $\Delta H_{vap}$ is $40.73 \, kJ \, mol^{-1}$ and the value of $\Delta S_{vap}$ is $109 \, J \, K^{-1} \, mol^{-1}$. At what temperature will water be in equilibrium with its vapor?

For the reaction at $298 \ K$,$2 \ A^{+}B \rightarrow C$. $\Delta H = 400 \ kJ \ mol^{-1}$ and $\Delta S = 0.2 \ kJ \ mol^{-1} \ K^{-1}$. The reaction will become spontaneous above $...... \ K$.

$A$ $4.50 \ g$ sample of methane occupies $12.7 \ L$ at $310 \ K$. Calculate the work done in $J$ when the gas undergoes isothermal expansion against a constant external pressure of $200 \ torr$ until the volume increases by $3.3 \ L$. (in $.99$)

Consider the graph of $Gibbs$ free energy $G$ vs. Extent of reaction. The number of statement$(s)$ from the following which are true with respect to points $(a)$,$(b)$,and $(c)$ is $.................$
$A$. Reaction is spontaneous at $(a)$ and $(b)$
$B$. Reaction is at equilibrium at point $(b)$ and non-spontaneous at point $(c)$
$C$. Reaction is spontaneous at $(a)$ and non-spontaneous at $(c)$
$D$. Reaction is non-spontaneous at $(a)$ and $(b)$