The correct option is A (A), (B), (C)
5CH3−4CH2−3CH−2C|BrH−1CH3β elimination−−−−−−−−→−HBr5CH3−4CH2−3CH=2CH−1CH3
(A) β−hydrogen is removed so it is a β− elimination reaction.
(B) Major product is most substituted alkene which is formed by Zaitsev's rule.
(C) In this elimination rection hydrogen halide (HBr) is getting removed, hence it is a dehydrohalogenation reaction.