A 1.0 mol sample of benzene is maintained at 1 atm. Which of the following changes will result in a positive value of q for the benzene system?
a) C6H6(g)→C6H6(l) at 80∘C
b) C6H6(s)→C6H6(l) at 5∘C
c) C6H6(g)→C6H6(s) at −20∘C
d) C6H6(l,80∘C)→C6H6(l,60∘C)