The correct option is B ΔSsystem>0 and ΔSsurrounding<0
This problem is based on assumption that total entropy change of universe is zero.
At 100∘C and 1 atmosphere pressure,
H2O⇌H2O(g) is at equilibrium.
For equilibrium, ΔStotal=0
and ΔSsystem+ΔSsurrounding=0
As we know during conversion of liquid to gas entropy of system increases, in a similar manner entropy of surrounding decreases.
∴ ΔSsystem>0 and ΔSsurrounding<0