The root of common culture in the 13th century was language, one of the…

The correct answer is Hindustani. In the 13th century, as Persian influence grew in India due to Islamic rule, a new linguistic blend emerged among the common people. Hindustani developed as a mixture of Persian and local Indian dialects, particularly from the Hindi region. This fusion created a common language that facilitated communication across diverse groups, forming the root of shared culture during that period. Persian was a dominant court language but not a mixture itself, while Sanskrit remained the classical scholarly language. Hindi as we know it today evolved later from this broader Hindustani foundation. Therefore, the language described as a mixture of two other languages in the 13th century is Hindustani.