Step 1: Understanding the first reaction (E2 elimination).
The substrate is a bromoalkane. On treatment with alcoholic KOH and heat (\(\Delta\)), it undergoes \(\beta\)-elimination (E2 reaction), leading to formation of an alkene by removal of HBr.
Step 2: Formation of alkene intermediate.
The base abstracts a \(\beta\)-hydrogen anti to the leaving group (Br), resulting in formation of the most substituted alkene according to Zaitsev’s rule. This gives a stable internal alkene intermediate.
Step 3: Ozonolysis reaction.
The alkene is then subjected to ozonolysis:
\[
(i)\ O_3 \quad (ii)\ Zn/H_2O
\]
Ozonolysis cleaves the double bond and converts each alkene carbon into carbonyl compounds (aldehydes or ketones depending on substitution).
Step 4: Identifying cleavage products.
Since the alkene formed is asymmetrical, cleavage produces a ketone on the more substituted carbon and an aldehyde on the terminal carbon. The carbon skeleton rearrangement matches the structure shown in option (4).
Step 5: Final confirmation.
Among all given products, only option (4) satisfies both:
- Correct elimination product
- Correct ozonolysis cleavage pattern
Final Answer:
\[
\boxed{\text{Option (4)}}
\]