The major product of which of the following reaction is not obtained by rearrangement reaction?

In the Friedel-Crafts alkylation of benzene with propyl chloride in the presence of (AlCl_3), the initially formed primary propyl carbocation is unstable and undergoes a (1,2)-hydride shift to generate the more stable secondary isopropyl carbocation. Hence, rearrangement occurs.

During the acid-catalyzed dehydration of tert-butyl alcohol, protonation of the hydroxyl group followed by loss of water produces a tertiary carbocation. Since this carbocation is already highly stable, it directly eliminates a proton to form the alkene without undergoing any rearrangement.

In the isomerization of alkanes using (AlCl_3/HCl), carbocation intermediates are formed and undergo hydride and alkyl shifts to produce more stable branched isomers. Therefore, rearrangement occurs.

In the acid-catalyzed dehydration of neopentyl-type alcohols, the initially formed carbocation rearranges through alkyl migration to generate a more stable tertiary carbocation before elimination. Hence, rearrangement occurs.

Therefore, among the given reactions, only reaction (B) does not involve rearrangement.

Hence, the correct answer is B.