Is increase of entropy the criterion for spontaneity ? Why ?

Is increases in entropy a criterion for spontaneity? Explain.

Enthalpy decreases is not the criterion for spontaneity. Why?

Is decrease in enthalpy a criterion for spontaneity? Explain.

Which of the following expression represent the criterion of spontaneity ?

Considering entropy (S) as a thermodynamics parameter, the criterion for the spontaneity of any process is