Spontaneity, Entropy, and Free Energy Question 4

Which of the following equations represents a reaction for which the standard entropy change is positive $(\Delta S^\circ \gt 0)$ ?

\ce{3O2(g)->2O3(g)}

\ce{2H2(g) + O2(g) -> 2H2O(l)}

\ce{CaCO3(g) -> CaO(s) + CO2(g)}

\ce{I2(g) + 2K(s) -> 2KI(s)}