How does spontaneity relate to the equilibrium constant in biochemical reactions?

Spontaneity is indicated by a negative Gibbs free energy change, which often correlates with a large equilibrium constant.

Spontaneity is indicated by a zero Gibbs free energy change.

Spontaneity is unrelated to the equilibrium constant.

Spontaneity is indicated by a positive Gibbs free energy change, which often correlates with a small equilibrium constant.