Correct answer: All of these
Explanation:
All the mentioned methods are effective in preventing corrosion:
- Painting: Creates a protective barrier that prevents moisture and oxygen from reaching the metal surface.
- Electroplating: Coats the metal with another metal (like chromium or zinc) to protect it from corrosion.
- Sacrificial electrode: A more reactive metal is used, which corrodes instead of the protected metal (e.g., using zinc to protect iron — called galvanization).
Hence, the correct answer is All of these.