For the reversible reaction between reactants A and B to form products C and D, which species are present at equilibrium? A+B --> C+D​

How does the value of the equilibrium constant show that a reaction reaches equilibrium very quickly? (a) the equilibrium constant is large. (b) the equilibrium constant is small. (c) the equilibrium constant is zero. (d) the value of the equilibrium constant does not show how quickly a reaction comes to equilibrium.