The IUPAC name of compound
`{:(CH_(3)-CH=C-CH_(2)-CH_(3)),(" |"),(" "CH_(2)-CH_(2)-CH_(3)):}`

Options

A. 3-Propylhex-3-ene
B. 3-Propylhex-2-ene
C. 3-Ethylhex-2-ene
D. 4-Ethylhex-4-ene

Explanation

To determine the IUPAC name of the given compound, we will follow these steps:

### Step 1: Identify the longest carbon chain
First, we need to identify the longest continuous carbon chain in the compound. The structure provided is:
```
CH3
|
CH3-CH=C-CH2-CH3
|
CH2-CH3
```
From the structure, we can see that the longest chain consists of 6 carbon atoms.

### Step 2: Number the carbon chain
Next, we will number the carbon chain to give the double bond the lowest possible number. We can start numbering from the end closest to the double bond:
1. CH3 (C1)
2. CH2 (C2)
3. C (C3)
4. CH2 (C4)
5. CH2 (C5)
6. CH3 (C6)

This gives us the numbering:
```
1 2 3 4 5 6
CH3-CH2-CH=CH-CH2-CH3
```

### Step 3: Identify substituents
Now, we need to identify any substituents attached to the main chain. In this case, there is an ethyl group (CH2-CH3) attached to the third carbon (C3).

### Step 4: Construct the name
Now we can construct the name based on the information we have:
- The longest chain has 6 carbons, which corresponds to "hex".
- The double bond is located between the second and third carbon, so we denote this as "hex-2-ene".
- The ethyl substituent is on the third carbon, so we denote this as "3-ethyl".

Combining all of this, we get the full IUPAC name:
**3-ethylhex-2-ene**

### Step 5: Verify the name
Finally, we can verify that the name corresponds to the structure we have drawn and the rules of IUPAC nomenclature.

### Final Answer:
The IUPAC name of the compound is **3-ethylhex-2-ene**.

---