For the reaction sequence given below, the correct statement(s) is(are):(In the options, \( X \) is any atom other than carbon and hydrogen, and it is different in \( P, Q \) and \( R \))
\( \text{C}-X \) bond length in \( P, Q \) and \( R \) follows the order \( Q > R > P \)
\( \text{C}-X \) bond enthalpy in \( P, Q \) and \( R \) follows the order \( R > P > Q \)
Relative reactivity toward \( \mathrm{S_{N}2} \) reaction in \( P, Q \) and \( R \) follows the order \( P > R > Q \)
\( pK_a \) value of the conjugate acids of the leaving groups in \( P, Q \) and \( R \) follows the order \( R > Q > P \)
