Which of the following represent incorrect numbering.

Options

A.
B.
C.
D.

Explanation

To determine which of the given options represents incorrect numbering according to IUPAC nomenclature, we will analyze each structure step by step.

### Step 1: Analyze the First Structure
1. **Identify the Structure**: The first structure has a triple bond and a double bond.
2. **Numbering**: Start numbering from the end closest to the double bond to give it the lowest locant.
- Numbering: 1 (double bond), 2, 3, 4, 5, 6 (triple bond).
- Locants: 1 and 6.
3. **Conclusion**: This numbering is correct as it gives the double bond the lowest number.

### Step 2: Analyze the Second Structure
1. **Identify the Structure**: The second structure also has a double bond.
2. **Numbering**: Start numbering from the end closest to the double bond.
- Numbering: 1 (double bond), 2, 3, 4, 5, 6.
- Locants: 1 and 4.
3. **Alternative Numbering**: If we start from the other end:
- Numbering: 1, 2, 3, 4, 5, 6 (triple bond).
- Locants: 2 and 5.
4. **Conclusion**: The first set of locants (1, 4) is lower than (2, 5), so the correct numbering should start from the end with the double bond. The provided numbering in this option is incorrect.

### Step 3: Analyze the Third Structure
1. **Identify the Structure**: The third structure has two double bonds.
2. **Numbering**: Start numbering from the end closest to the first double bond.
- Numbering: 1 (first double bond), 2, 3, 4, 5, 6, 7.
- Locants: 1, 4, 6.
3. **Alternative Numbering**: Start from the other end:
- Numbering: 1, 2, 3, 4, 5, 6, 7.
- Locants: 1, 3, 6.
4. **Conclusion**: The first set of locants (1, 4, 6) is lower than (1, 3, 6), so this numbering is correct.

### Step 4: Analyze the Fourth Structure
1. **Identify the Structure**: The fourth structure has a similar arrangement.
2. **Numbering**: Start numbering from the end closest to the first double bond.
- Numbering: 1 (first double bond), 2, 3, 4, 5, 6, 7.
- Locants: 1, 4, 6.
3. **Alternative Numbering**: Start from the other end:
- Numbering: 1, 2, 3, 4, 5, 6, 7.
- Locants: 1, 2, 3, 4.
4. **Conclusion**: The first set of locants (1, 4, 6) is lower than (1, 2, 3, 4), so this numbering is also correct.

### Final Answer
After analyzing all the options, the incorrect numbering is found in **Option 2**.

---