1. $\beta$-Elimination: The reaction involves the removal of a hydrogen atom from the $\beta$-carbon (the carbon adjacent to the one holding the halogen) and the halogen from the $\alpha$-carbon. Hence, it is a $\beta$-elimination reaction .
2. Zaitsev Rule: In dehydrohalogenation, if more than one alkene can be formed, the major product is the more substituted alkene (Zaitsev product). For 2-bromopentane, pent-2-ene (more substituted) is the major product compared to pent-1-ene .
3. Dehydrohalogenation: The reaction entails the elimination of a hydrogen halide (HBr), so it is termed dehydrohalogenation .
4. Dehydration: This term specifically refers to the removal of a water molecule ($H_2O$), typically from alcohols (e.g., ethanol to ethene) . Since 2-bromopentane is a haloalkane, not an alcohol, this is not a dehydration reaction.

Therefore, statements (a), (b), and (c) are correct.