Task: Question Answering
Input (English): Question: A spontaneous process is characterized because: 
 Options:  <1> In isolated systems the entropy decreases (ΔS <0). <2> At constant pressure and temperature, the Gibbs energy decreases (ΔG <0). <3> At constant pressure and temperature, the Helmholtz energy decreases (ΔA <0). <4> At constant volume and temperature, the Gibbs energy increases (ΔG> 0). <5> It is reversible.
Output (English): 2