Article 21 is related to which of the following fundamental rights?

The correct answer is Protection of Life and Personal Liberty.

Step-by-Step Explanation:

1. Understanding Article 21 of the Indian Constitution:
Article 21 is one of the most vital fundamental rights guaranteed under Part III of the Constitution of India. It states: "No person shall be deprived of his life or personal liberty except according to procedure established by law." This right is available to both citizens and non-citizens alike.

2. Analyzing the Options:
- Protection of Language, Culture of Minorities: This is covered under Article 29 of the Constitution.
- Freedom of Speech: This is a part of the Right to Freedom guaranteed under Article 19(1)(a).
- Freedom to Manage Religious Affairs: This is covered under Article 26 of the Constitution.
- Protection of Life and Personal Liberty: This is the exact subject matter of Article 21.

3. Conclusion:
Therefore, Article 21 is directly related to the Protection of Life and Personal Liberty.