For a given exothermic reaction, $K_P$ and $K_P'$ are the equilibrium constants at temperatures $T_1$ and $T_2$ respectively. Assuming that heat of reaction is constant in temperatures range between $T_1$ and $T_2$ , it is readily observation that:

Question

( A ) $K_P < K_P'$
( B ) $K_P = \frac{1}{K_P'}$
( C ) $K_P > K_P'$
( D ) $K_P = K_P'$