In which of the following will entropy and enthalpy factors favour the establishment of an equilibrium?

A$.CaC{O}_{3(s)}+178kJ{?}^{?}Ca{O}_{(s)}+C{O}_{2(g)}$

B$.M{g}_{(s)}+2HC{l}_{(aq)}{?}^{?}MgC{l}_{2(aq)}+H_{2(g)}+425kJ$

C$.2C_{(s)}+2H_{2(g)}{?}^{?}{C}_2{H}_{4(g)}$

$H=+52\mathrm{.}3kJ$

D$.2C_2{H}_{6(g)}+7O_{2(g)}{?}^{?}4C{O}_{2(g)}+6H_2{O}_{(g)}$

$H=-1560kJ$