Correct option is B
Fragmentation reactions, which are similar to β-elimination reactions, can be useful for the formation of alkenes, particularly from carbocyclic compounds. Fragmentation reactions occur most easily from conformationally locked 1,3-difunctionalized compounds, in which the breaking C-X and C-C bonds (highlighted) are aligned antiperiplanar.
Fragmentation reactions may be used to prepare cyclic or acyclic alkenes from cyclic precursors. The stereochemistry of the alkene can be set up by controlling the relative stereochemistry of the cyclic substrate, a process that is normally relatively easy.
Sodium hydride is the chemical compound with the empirical formula NaH. This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis.
