Which of the following pairs of compounds are not position isomers?

Options

A.
B.
C.
D.

Explanation

To determine which pairs of compounds are not position isomers, we need to analyze each option carefully. Position isomers are compounds that have the same molecular formula and functional groups but differ in the position of the functional group on the carbon chain.

### Step-by-Step Solution:

1. **Identify the Compounds**: Start by listing the pairs of compounds given in the question.

2. **Analyze Each Pair**:
- **First Pair**: Check if the functional group changes position between the two compounds.
- For example, if one compound has a functional group at position 1 and the other at position 3, they are position isomers.
- **Second Pair**: Look for the presence of carboxylic acids. Remember that carboxylic acids cannot exhibit position isomerism because the carboxylic carbon is always part of the parent chain and must be numbered as position 1.
- **Third Pair**: Similar to the first pair, check if the functional group changes position. If one compound has the functional group at position 1 and the other at position 2, they are position isomers.
- **Fourth Pair**: Again, analyze the position of the functional groups. If they are at different positions, they are position isomers.

3. **Conclusion**: After analyzing all pairs, identify which pair does not show position isomerism.
- In this case, the pair involving carboxylic acids is the correct answer because carboxylic acids cannot exhibit position isomerism.

### Final Answer:
The pair of compounds that are not position isomers is the one that includes carboxylic acids.