The equilibrium constants of the following isomerisation reaction at 400 K and 298 K are 2.07 and 3.42 respectively.

Which of the following is/are correct?
I. The reaction is exothermic
II. The reaction is endothermic
III. At 400 K 50 percent of cis-butene and 50 percent of trans-butene are present at equilibrium
IV. Both at 298 K and 400 K, $$k_1 = k_{-1}$$

A

I and IV

B

II and IV

C

I and III

D

I only