How do thermodynamics and kinetics control this reaction?
Initially no B and C exist. At short times as $k_1 &gt; k_2$ production of B is favoured over C. (The initial amounts of B and C are so small that back reactions can be ignored wrt. forwards ones.) At long times  equilibrium constants matter and as the equilibrium constant $K_2$ is greatest this is favoured to produce C over B.