A compound (A) is formed by the reaction of ethylene with bromine which on reacting with aqueous KOH gives a compound (B). The compound (B) can also be prepared by the reaction of ethylene with the following:

Options

A. Baeyer’s reagent
B. Oxygen in the presence of silver catalyst and then acidic hydrolysis
C. performic acid and the product undergoes acidic hydrolysis
D. All of the above

Answer

To solve the problem, we will follow these steps:

### Step 1: Identify Compound A
The question states that compound A is formed by the reaction of ethylene (C2H4) with bromine (Br2). This reaction is an addition reaction where bromine adds across the double bond of ethylene.

**Chemical Reaction:**
\[ C_2H_4 + Br_2 \rightarrow C_2H_4Br_2 \]

**Compound A:** 1,2-dibromoethane (C2H4Br2)

### Step 2: Identify Compound B
The question mentions that compound A (1,2-dibromoethane) reacts with aqueous KOH to form compound B. In this case, KOH acts as a nucleophile and replaces one of the bromine atoms with a hydroxyl group (OH), resulting in the formation of ethylene glycol.

**Chemical Reaction:**
\[ C_2H_4Br_2 + KOH \rightarrow C_2H_4(OH)_2 + KBr \]

**Compound B:** Ethylene glycol (C2H6O2)

### Step 3: Alternative Preparations for Compound B
The question asks how compound B (ethylene glycol) can also be prepared from ethylene. We can consider the following methods:

1. **Baeyer's Reagent (Acidified KMnO4):**
- Ethylene reacts with Baeyer's reagent, which oxidizes the double bond and forms ethylene glycol.
- **Chemical Reaction:**
\[ C_2H_4 + [O] \rightarrow C_2H_6O_2 \]

2. **Reaction with Oxygen in the Presence of Silver Catalyst:**
- Ethylene can react with oxygen in the presence of a silver catalyst to form an epoxide, which upon acid hydrolysis yields ethylene glycol.
- **Chemical Reaction:**
\[ C_2H_4 + O \xrightarrow{Ag} \text{Epoxide} \xrightarrow{H_2O/H^+} C_2H_6O_2 \]

3. **Reaction with Performic Acid followed by Acid Hydrolysis:**
- Ethylene reacts with performic acid to form an epoxide, which upon acid hydrolysis also yields ethylene glycol.
- **Chemical Reaction:**
\[ C_2H_4 + \text{Performic Acid} \rightarrow \text{Epoxide} \xrightarrow{H_2O/H^+} C_2H_6O_2 \]

### Conclusion
All three methods mentioned above can be used to prepare compound B (ethylene glycol) from ethylene. Therefore, the answer to the question is that compound B can be prepared by all of the above methods.

### Final Answer:
All of the above methods can prepare compound B (ethylene glycol).

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