Supply the reagents in the following sequence of reations :
(i) `CH_(3)CH_(2)CH_(2)Br overset((A))(to) CH_(3) CH= CH_(2) overset((B))(to) CH_(3) CHBr - CH_(2) Br overset((C ))(to) CH_(3)-C -=CH overset((D))(to) CH_(3) -overset(O)overset(||)(C)-CH_(3)`

Explanation

To solve the given question, we need to identify the reagents for each step of the reaction sequence. Let's break it down step by step.

### Step 1: Conversion of `CH₃CH₂CH₂Br` to `CH₃CH=CH₂`
- **Reagent (A)**: We need to eliminate the bromine atom (Br) to form a double bond. This can be achieved through dehydrohalogenation using **Alcoholic KOH** (potassium hydroxide in alcohol) in the presence of heat.

**Reaction**:
\[
CH₃CH₂CH₂Br \xrightarrow{Alcoholic\ KOH, \Delta} CH₃CH=CH₂ + HBr
...