Final answer:
The reaction that will not give the indicated product is option (a), which shows a substitution reaction when an elimination reaction is expected.
Step-by-step explanation:
The reaction that will not give the indicated product is option (a) CH₃CH₂Br + KOH → CH₂=CH₂ + KBr + H₂O. This is because the reaction conditions described are typically for a substitution reaction, not an elimination reaction needed to produce ethylene (CH₂=CH₂). For the reaction to yield ethylene, the conditions must favor dehydrohalogenation, typically requiring a higher temperature and the use of alcoholic KOH, not aqueous KOH.
Each of the other reactions listed in options (b), (c), and (d) are elimination reactions which are likely to produce the products indicated under the correct reaction conditions. For instance, in option (d) CH₂=CHCH₂Br + KOH → CH₃CH=CH₂ + KBr + H₂O, an alcoholic KOH solution would promote the formation of propylene (CH₃CH=CH₂) via dehydrohalogenation.