Identify X in the following sequence of reactions
`CH_(3) - underset(Br)underset(|)CH-underset(Br)underset(|)-CH_(2)-CH_(2)-CH_(3) overset(1. NaNH_2)underset(2. "Na in liquid" NH_3) rarr X `

Options

A. `CH_(3) - underset(Br)underset(|)CH-underset(NH_2)underset(|)CH-CH_(2)CH_(2)CH_(3)`
B.
C.
D. `CH_(3)-underset(NH_2)underset(|)CH-underset(NH_2)underset(|)CH-CH_(2)CH_(2)CH_(3)`

Explanation

To solve the problem, we need to analyze the given sequence of reactions step by step.

### Step 1: Understanding the Starting Material
The starting material is:
\[ \text{CH}_3 - \text{Br} \quad \text{(1-bromopropane)} \]
\[ \text{CH} - \text{Br} \quad \text{(2-bromopropane)} \]
\[ \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \quad \text{(propane)} \]

This can be represented as:
\[ \text{CH}_3 - \text{Br} - \text{CH} - \text{Br} - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]

### Step 2: Reaction with NaNH₂
When we treat the compound with sodium amide (NaNH₂), it acts as a strong base and will facilitate an elimination reaction (E2 mechanism). In this case, two moles of HBr will be eliminated from the molecule.

### Step 3: Elimination Reaction
The elimination of HBr will lead to the formation of a triple bond (alkyne). The reaction can be summarized as follows:
- The bromine atoms are removed, and hydrogen atoms are also removed from adjacent carbon atoms.
- This results in the formation of a terminal alkyne.

The product after this step will be:
\[ \text{CH}_3 - \text{C} \equiv \text{C} - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]
This is 1-heptyne.

### Step 4: Reduction with Sodium in Liquid Ammonia
The next step involves treating the alkyne with sodium in liquid ammonia. This process is known as Birch reduction, which converts alkynes to trans-alkenes.

### Step 5: Formation of the Final Product
The Birch reduction will lead to the formation of a trans-alkene. The product will be:
\[ \text{CH}_3 - \text{C} = \text{C} - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]
This compound is 1-heptyne, which will be a trans-alkene.

### Final Answer
Thus, the compound X that results from the sequence of reactions is:
\[ \text{CH}_3 - \text{C} = \text{C} - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]