JEE Advanced 2023 Chemistry question on Chemical Kinetics

The plot of $\log k_f$ versus $^1\!/_T$ for a reversible reaction A (g) $\rightleftharpoons$ P (g) is shown.

Pre-exponential factors for the forward and backward reactions are $10^{15}$ s$^{-1}$ and $10^{11}$ s$^{-1}$, respectively. If the value of $\log K$ for the reaction at 500 K is 6, the value of $|\log k_b|$ at 250 K is ___.

[K = equilibrium constant of the reaction
$k_f$ = rate constant of forward reaction
$k_b$ = rate constant of backward reaction]