Consider the following pairs:
List I (Type of Writ) — List II (Description)
1. Habeas Corpus — It protects an individual against unlawful imprisonment.
2. Mandamus — It prevents a court from exceeding its jurisdiction.
3. Prohibition — It directs a public servant to perform his legal duties.
4. Certiorari — It prevents illegal usurpation of public office by a person.
How many pairs given above are correctly matched?