Which one of the following are prepared by electrolytic method ?
I. Mg II. S III. Sulfur IV. `F_2`

Options

A. I and II
B. II and III
C. III and IV
D. I and IV

Explanation

To determine which of the given elements are prepared by the electrolytic method, we will analyze each option one by one.

### Step-by-Step Solution:

1. **Understanding Electrolytic Method**:
The electrolytic method involves the use of electrical energy to drive a non-spontaneous chemical reaction. This method is typically used for the extraction of reactive metals and certain non-metals.

2. **Analyzing Each Option**:
- **I. Mg (Magnesium)**:
Magnesium is a highly reactive metal. It is indeed prepared by the electrolytic method, specifically through the electrolysis of molten magnesium chloride (MgCl₂). During this process, magnesium ions are reduced at the cathode to form magnesium metal.

- **II. S (Sulfur)**:
Sulfur is a non-metal and is not typically prepared by the electrolytic method. It is usually obtained from natural sources or through chemical processes, not by electrolysis.

- **III. Sulfur**:
This is simply another representation of sulfur (S) and does not change the analysis. It is still not prepared by the electrolytic method.

- **IV. F₂ (Fluorine)**:
Fluorine is a highly reactive non-metal and is prepared by the electrolytic method. It is produced through the electrolysis of potassium fluoride (KF) or other fluoride salts. During this process, fluoride ions are oxidized at the anode to form fluorine gas.

3. **Conclusion**:
Based on the analysis, the elements prepared by the electrolytic method are:
- **I. Mg (Magnesium)**
- **IV. F₂ (Fluorine)**

### Final Answer:
The elements prepared by the electrolytic method are **I. Mg and IV. F₂**.

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