Which of the following reactions can be used to prepare `CH_(3)-underset(C_(2)H_(5))underset(|)overset(OH)overset(|)C-C_(6)H_(5)`

Options

A. `CH_(3)-overset(O)overset(||)C-C_(6)H_(5)+C_(2)H_(5)MgBrrarr[ ] overset(H_(3)O^(+))rarr`
B. `C_(2)H_(5)-overset(O)overset(||)C-C_(6)H_(5)+CH_(3)MgBrrarr[] overset(H_(3)O^(+))rarr`
C. `CH_(3)-overset(O)overset(||)C-C_(2)H_(5)+C_(6)H_(5)MgBrrarr[] overset(H_(3)O^(+))rarr`
D. `CH_(3)-underset(C_(2)H_(5))oversetoverset(Br)overset(|)(C)-C_(6)H_(5)underset(Delta)overset(Alc. KOH)rarr`

Answer

To solve the question of which reactions can be used to prepare the compound `CH₃-CH(OH)-C(C₂H₅)-C₆H₅`, we will analyze the reactions provided and their outcomes step by step.

### Step 1: Understanding the Target Compound
The target compound is a tertiary alcohol with the following structure:
- A methyl group (CH₃)
- An ethyl group (C₂H₅)
- A phenyl group (C₆H₅)

This compound can be represented as:
```
CH₃
|
C₂H₅-C(OH)-C₆H₅
```

### Step 2: Analyzing the Reactions
We need to determine which reactions can lead to the formation of this tertiary alcohol. The reactions mentioned involve the use of Grignard reagents and alcoholic KOH.

1. **Grignard Reagent Reactions**:
- When a Grignard reagent reacts with a ketone, it forms a tertiary alcohol after hydrolysis. The general reaction is:
\[ R-MgX + R'CO + H_2O \rightarrow R-R'-C(OH)-R'' \]
- Here, R, R', and R'' can be CH₃, C₂H₅, and C₆H₅ respectively.

2. **Alcoholic KOH Reaction**:
- Alcoholic KOH typically leads to an elimination reaction, producing an alkene rather than an alcohol. The reaction can be represented as:
\[ R-CH(Br)-R' + KOH \rightarrow R-CH=R' + HBr \]
- This means that this reaction will not yield the desired alcohol.

### Step 3: Conclusion on the Reactions
- **Reactions A, B, and C**: These involve Grignard reagents and will yield the desired tertiary alcohol.
- **Reaction D**: This uses alcoholic KOH, which will lead to the formation of an alkene instead of the alcohol we want.

### Final Answer
The reactions that can be used to prepare the compound `CH₃-CH(OH)-C(C₂H₅)-C₆H₅` are:
- **A, B, and C** (Grignard reagent reactions).
- **D** cannot be used as it leads to an alkene.