At Room Temperature Cyclohexane Exists Almost Exclusively in the Chair

At room temperature cyclohexane exists almost exclusively in the chair conformation (99.99%) . But at 800°C, 30% of the cyclohexane molecules exist in the twist-boat conformation. What is the value of the equilibrium constant for the following reaction at 800°C?
C₆H₁₂(chair) C₆H₁₂(twist-boat)

A) 0.30
B) 2.3
C) 0.23
D) 0.43
E) 0.77