Select the structure with correct numbering in the chain:

Options

A. `Coverset(5)H_(2)=Coverset(4)H-Coverset(3)H_(2)-overset(2)(C)=overset(1)(C)H`
B. `overset(1)CH_(3)-overset(2)(C)H=overset(3)(C)H-overset(4)(C)H_(2)-overset(5)(C)=overset(6)(C)H`
C. `Coverset(7)(H_(2))=Coverset(6)(H)-Coverset(5)(H)=overset(4)(C)H-overset(3)(C)H_(2)-overset(2)(C)H=overset(1)(C)H_(2)`
D. `Coverset(1)(H_(2))=Coverset(2)(H)-Coverset(3)(H)=overset(4)(C)H-overset(5)(C)H_(2)-overset(6)(C)=overset(7)(C)H`

Answer

To determine the structure with the correct numbering in the chain, we need to follow these steps:

### Step 1: Identify the Longest Carbon Chain
- Look at each structure and identify the longest continuous carbon chain. This will be the basis for numbering.

### Step 2: Number the Chain
- Start numbering the carbon chain from the end that gives the substituents (alkenes, functional groups, etc.) the lowest possible numbers. This is crucial for proper IUPAC nomenclature.

### Step 3: Analyze Each Structure
- **Structure A**: Numbering is done from the end closest to the first alkene. This gives the lowest possible numbers to the double bonds. Thus, Structure A is correct.

- **Structure B**: Numbering from left to right gives the double bond at positions 2 and 5 (2-alkene and 5-alkene). However, if we number from the right, we can achieve 1-alkene and 4-alkene, which is lower. Therefore, Structure B is incorrect.

- **Structure C**: Similar to Structure A, the numbering gives the lowest possible numbers to the double bonds. Thus, Structure C is also correct.

- **Structure D**: The numbering from either end gives the same lowest numbers for the substituents. Therefore, Structure D is correct as well.

### Step 4: Conclusion
- The structures with correct numbering in the chain are A, C, and D.

### Final Answer
- The correct structures with proper numbering are A, C, and D.

---