The term ‘Aryan’ denotes

The term “Aryan” is primarily a linguistic designation referring to speakers of the Indo‑Aryan/Indo‑Iranian branch of Indo‑European languages — effectively a speech group. Modern scholarship treats Aryan as a language‑group label rather than a biological or racial category; 19th–20th century racial uses are now rejected and considered misappropriations of the linguistic term [2]. Vedic and Avestan texts use forms of arya as a self‑designation tied to cultural and linguistic identity, and scholarly sources emphasize its status as a linguistic/ethno‑cultural label rather than proof of a distinct superior race or simply a nomadic people [2]. Thus option 3 (a speech group) is correct.

Sources

1. [1] https://unesdoc.unesco.org/ark:/48223/pf0000064836
2. [2] https://www.britannica.com/topic/Aryan