Which reactions have a positive ΔSrxn?

Question

A(g)+2B(g)⟶2C(g)
A(s)+2B(g)⟶C(g)
2A(g)+B(g)⟶4C(g)
2A(g)+B(s)⟶3C(g)

Answer 1

3 and 4 increase in mols gas from reactant to product. dS increases.