Explanation

Hazrat Ali R.A is generally cited as the first Qazi appointed by Hazrat Abubakar R.A. Hazrat Umar R.A was a prominent companion but not specifically named as the first Qazi in this context. Hazrat Usman R.A's role is distinct from that of the first appointed Qazi. Hazrat Bilal R.A served other important roles and is not cited as the first Qazi.