Which of the following conditions results in a spontaneous chemical reaction?

The standard reaction Gibbs energy for a chemical reaction at an absolute temperature $T$ is given by $\Delta_{r}G^{o} = A - BT$,where $A$ and $B$ are non-$zero$ constants. Which of the following is $TRUE$ about this reaction?

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

Which of the following statements is correct?

For the reaction $2 \ NO_{2(g)} \rightleftharpoons N_2O_{4(g)}$,when $\Delta S = -176.0 \ J \ K^{-1} \ mol^{-1}$ and $\Delta H = -57.8 \ kJ \ mol^{-1}$,the magnitude of $\Delta G$ at $298 \ K$ for the reaction is $...... \ kJ \ mol^{-1}$. (Nearest integer)

For a reaction,$\Delta H = -40 \, kJ$ and $\Delta S = -50 \, J/K$. At what temperature range will it change from spontaneous to non-spontaneous?