Final answer:
Hazrat Ali is recognized for contributing to the style of Kufic writing, which is an angular script used for early Qur'anic manuscripts and other inscriptions in Islamic art.
Step-by-step explanation:
Hazrat Ali is credited for developing a certain style of Kufic writing. The Arabic script in the form of art known as Kufic is an angular script frequently used in Qur'ans, named after the town of Kufa. However, the specific styles of Arabic calligraphy mentioned in the options provided in the question are Naskh, Diwani, Thuluth, and Riqa'a. None of these styles are directly associated with Hazrat Ali. Typically, the oldest form of Arabic calligraphy is the Kufic script, which became prevalent across the Abbasid caliphate. Kufic script is known for its angular form and was used in early Qur'anic manuscripts. Symbols for marking verses and luxurious embellishments such as gold leaf were features of this script, especially in high-quality manuscripts.