Answer:
C. spontaneous at all temperatures
Step-by-step explanation:
The spontaneity of reaction is determined by the sign of the gibbs free energy.
A negative sign denotes that the reaction is spontaneous, positive sign means the reaction is not spontaneous.
From the question;
ΔS° = +253 J/K
ΔH° = -125 kJ/mol
ΔG = ΔH° - TΔS°
From the data given, the condition in which we can obtain a negative value of G, is at any value of T.
For any value of T, G would always be a negative value.
This means the correct option is option C.