An organic compound (A) `(C_(10)H_(20))` on reductive ozonolysis gives `2-` methyl butanal. Based on this information, answer the following question.
If the stereochemistry about the double bond in (A) is trans, the total number of enantiomers for (A) is :

Options

A. None
B. 2
C. 4
D. 6

Answer

To solve the problem, we need to determine the total number of enantiomers for the compound (A) given that it has a trans double bond and produces 2-methylbutanal upon reductive ozonolysis.

### Step-by-Step Solution:

1. **Identify the Compound (A)**:
- The molecular formula of compound (A) is \(C_{10}H_{20}\).
- The ozonolysis reaction suggests that (A) contains a double bond, which upon ozonolysis produces two molecules of 2-methylbutanal.

2. **Understanding the Ozonolysis Product**:
- The product, 2-methylbutanal, has the structure:
\[ \text{CH}_3-\text{CH}(C_2\text{H}_5)-\text{CHO} \]
- This indicates that the double bond in (A) must be positioned such that when it is cleaved, it yields this specific aldehyde.

3. **Structure of Compound (A)**:
- Given that (A) produces 2-methylbutanal, we can deduce that (A) must have a structure that includes a double bond leading to the formation of this product.
- A possible structure for (A) could be 2,4-decadiene (trans configuration), which can be represented as:
\[ \text{CH}_3-\text{CH}=\text{CH}-\text{CH}=\text{CH}-\text{CH}_2-\text{CH}_3 \]
- This structure has trans double bonds.

4. **Identify Chiral Centers**:
- In the structure of (A), we need to identify the chiral centers. A chiral center is a carbon atom that is attached to four different groups.
- In the trans configuration of 2,4-decadiene, there are two chiral centers at the positions where the double bonds are located.

5. **Calculate the Number of Enantiomers**:
- The formula to calculate the number of enantiomers is given by \(2^n\), where \(n\) is the number of chiral centers.
- Since we have identified 2 chiral centers, we can substitute \(n = 2\):
\[ \text{Total Enantiomers} = 2^n = 2^2 = 4 \]

6. **Consider the Stereochemistry**:
- The problem states that the stereochemistry about the double bond in (A) is trans. This means that the configuration of the double bond is fixed, which does not affect the total number of enantiomers derived from the chiral centers.

### Final Answer:
The total number of enantiomers for compound (A) is **4**.