The _______________ referred to the people east of the Indus as "Hindu", their land as "Hindustan", and their language as "Hindavi".

Turks

The correct answer is Option 4: Turks

The TURKS referred to the people east of the Indus as "Hindu", their land as "Hindustan", and their language as "Hindavi".

The term “Hindu” was derived from an Old Persian word, used c. sixth-fifth centuries BCE, to refer to the region east of the river Sindhu (Indus). The Arabs continued the Persian usage and called this region “al-Hind” and its people “Hindi”. Later the Turks referred to the people east of the Indus as “Hindu”, their land as “Hindustan”, and their language as “Hindavi”. None of these expressions indicated the religious identity of the people. It was much later that the term developed religious connotations.