Correct Answer - B
A widely used method for synthesizing alkenes is the elimination of `HX` from adjacent atoms of an alkyl halide. For the formation of a double bond, the hydrogen must come from a `C` atom that is adjacent to the `C` holding the halogen.
The `C` atom that functional group (e.g, the halogen atom is alkyl halides) is commonly called the `alpha`-carbon (alpha-carbont).
`-overset(betaH)overset(beta|)C-underset(X)underset(|)overset(|alpha)C-overset(Hbeta)overset(|beta)C`
Any `C` atom directly attached to the `alpha-C` is a `beta-C` (beta carbon). An `H` atom directly attached to the `beta-C` atom is called a `beta`-hydrogen atom.
Since the `H` atom that is eliminated in dehydrohalogentation is from the `beta`-carbon atom, dehydrohalogenation is often called `beta`-elimination. It is referred to as `1,2`-elimination.
