Which of the following represent correct pair of homologous ?

Options

A.
B. `Me-OH` & `MeCH_(2)-CH_(2)OH`
C. `H-oversetoverset(O)(||)( C)-O-CH_(2)` & `CH_(3)-oversetoverset(O)(||)( C)-O-CH_(3)`
D.

Explanation

To determine which pairs of compounds represent homologous series, we need to understand the definition of a homologous series. A homologous series is a group of compounds that have the same functional group and similar chemical properties, differing from each other by a constant unit, typically a -CH2- group.

### Step-by-Step Solution:

1. **Understanding Homologous Series**:
- A homologous series consists of compounds that share the same functional group and differ by a -CH2- unit.
- The general formula for alkanes is CnH2n+2.

2. **Analyzing the Options**:
- We need to evaluate each option to see if they fit the criteria of a homologous series.

3. **Option A**:
- Compounds: One has an OH group (alcohol) and the other has a CH2OH group.
- Analysis: The functional groups are different (one is a primary alcohol and the other is a phenolic compound). Thus, they do not form a homologous series.

4. **Option B**:
- Compounds: One is CH3OH (methanol) and the other is CH3CH2CH2OH (butanol).
- Analysis: Both compounds have the same functional group (alcohol) and differ by a -CH2- unit. Therefore, this is a correct pair of homologous compounds.

5. **Option C**:
- Compounds: Both have ester functional groups (RCOOR).
- Analysis: If one compound is RCOOR and the other is RCOOCH2R, they differ by a -CH2- unit while maintaining the same functional group. Hence, this is also a correct pair of homologous compounds.

6. **Option D**:
- Compounds: One is CH3CH2NH2 (ethylamine) and the other is CH3CH2N(CH3)H.
- Analysis: Although there is an increase in the number of methyl groups, the functional groups are different (primary amine vs. secondary amine). Therefore, they do not form a homologous series.

### Conclusion:
The correct pairs of homologous compounds are **Option B** and **Option C**.