Final answer:
The Indo-Iranian branch can be divided into the Indo-Aryan, Iranian, and Nuristani language groups, each significant in different regions of South Asia and parts of the Middle East.
Step-by-step explanation:
The Indo-Iranian branch of languages can be divided into several language groups. This branch itself forms a significant part of the wider Indo-European language family, which encompasses a variety of languages spread across Europe and Asia. The primary language groups under the Indo-Iranian branch are the Indo-Aryan languages, the Iranian languages, and the Nuristani languages.
The Indo-Aryan languages are spoken mainly in the Indian subcontinent and include languages like Hindi, Bengali, and Punjabi. In contrast, the Iranian languages include Farsi (Persian) in Iran as well as other languages spoken in parts of the Middle East and Central Asia. The Nuristani languages, however, are a smaller group of languages spoken primarily in the Nuristan province of Afghanistan. These divisions within the Indo-Iranian branch reflect the historical and cultural dynamics that have shaped language development in this linguistically rich region.