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 )

Options

1. AC-X bond length in P , Q and R follows the order Q > R > P .
2. BC-X bond enthalpy in P , Q and R follows the order R > P > Q .
3. CRelative reactivity toward S _ N 2 reaction in P , Q and R follows the order P > R > Q .
4. Dp K_ a value of the conjugate acids of the leaving groups in P , Q and R follows the order R > Q > P .