Major product of the given reaction is
`CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)C-underset(CI)underset(|)(CH)-CH_(3)overset(C_(2)H_(5)O^-)rarr`

Options

A. `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)C-underset(OC_(2)H_(5))underset(|)(CH)-CH_(3)`
B. `CH_(3)-underset(CH_(3))underset(|)overset(CH_(3))overset(|)C-CH=CH_(2)`
C. `CH_(3)-overset(CH_(3))overset(|)C=underset(CH_(3))underset(|)C-CH_(3)`
D. `CH_(3)-underset(OC_(2)H_(5))underset(|)overset(CH_(3))overset(|)C-overset(CH_(3))overset(|)(CH)-CH_(3)`

Explanation

To determine the major product of the given reaction, we will analyze the provided structure and the reaction conditions step by step.

### Step 1: Identify the Reactants
The reactant is a compound that has a carbon chain with several methyl groups and a chloro (Cl) substituent. The base used in the reaction is ethoxide ion (C2H5O^-).

### Step 2: Recognize the Reaction Type
Since the reaction involves an alkyl halide (the compound with the Cl substituent) reacting with a strong base (C2H5O^-), it indicates an E2 elimination reaction. In an E2 reaction, the base abstracts a beta hydrogen while the leaving group (Cl) departs, resulting in the formation of a double bond.

### Step 3: Identify the Beta Hydrogens
In the structure, we need to identify the beta positions relative to the carbon that is attached to the Cl. The carbon with the Cl is the alpha position. The adjacent carbons are the beta positions.

- The beta positions in this case are the carbons next to the alpha carbon.
- We need to check which of these beta carbons has hydrogen atoms available for abstraction.

### Step 4: Abstracting the Beta Hydrogen
In this case, we find that one of the beta positions has hydrogen atoms available for abstraction. The base (C2H5O^-) will abstract one of these beta hydrogens.

### Step 5: Simultaneous Bond Breaking
During the E2 elimination, the bond between the beta carbon and the hydrogen (C-H) and the bond between the alpha carbon and the leaving group (C-Cl) will break simultaneously.

### Step 6: Formation of the Alkene
After the abstraction of the hydrogen and the departure of the Cl, a double bond will form between the alpha carbon and the beta carbon from which the hydrogen was abstracted. This results in the formation of an alkene.

### Step 7: Write the Major Product
The major product will be the alkene formed after the elimination reaction. The structure will have a double bond between the alpha carbon and the beta carbon, along with the remaining methyl groups.

### Conclusion
The final product of the reaction is an alkene with the structure that reflects the elimination process.

### Answer
The major product of the given reaction is an alkene.

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