In the given reaction
`overset(Br)overset(|)(CH_2)-(CH_2)_(3)-CH_2OH underset("Toluene" 140^@C)overset(NaOH)(rarr)(X)`
'X' will be

Options

A. `overset(OH)overset(|)(CH_2)-(CH_2)_(4)-CH_2OH`
B. `CH_2=CH-(CH_2)_(3)-CH_2OH`
C. `CH_3-overset(OH)overset(|)(CH)-(CH_2)_(3)-CH_2OH`
D.

Answer

To solve the given reaction step by step, we need to analyze the reactants and the conditions provided.

### Step 1: Identify the Reactants
The reactant is 1-bromopentanol, which can be represented as:
\[ \text{Br-CH}_2-\text{CH}_2-\text{CH}_2-\text{CH}_2\text{OH} \]

### Step 2: Understand the Reaction Conditions
The reaction is conducted in the presence of sodium hydroxide (NaOH) and toluene at a temperature of 140°C. This indicates that we are likely dealing with a nucleophilic substitution or elimination reaction.

### Step 3: Determine the Reaction Mechanism
At elevated temperatures, NaOH can facilitate the elimination of bromide (Br) from the alkyl halide. This is typically done through an E2 mechanism, especially since we have a good leaving group (Br) and a strong base (NaOH).

### Step 4: Predict the Product
The elimination reaction will lead to the formation of an alkene. In this case, the bromine atom will be removed, and a double bond will be formed between the adjacent carbon atoms.

The structure of the product (alkene) will be:
\[ \text{CH}_2=\text{CH}-\text{CH}_2-\text{CH}_2\text{OH} \]
This compound is 1-pentene with a hydroxyl group (alcohol) on the terminal carbon.

### Step 5: Finalize the Product
The final product 'X' will be:
\[ \text{X} = \text{CH}_2=\text{CH}-\text{CH}_2-\text{CH}_2\text{OH} \]

### Conclusion
Thus, the product 'X' formed in the reaction is an alkene with an alcohol functional group.