Which of the following were the barriers that Al Biruni felt obstructed the understanding of the culture that he observed in the Indian subcontinent as compared to practices with which travellers were familiar?

a. Language b. The difference in religious beliefs and practices c. The insularity of the local population d. The caste system

This is the correct answer as Al Biruni identified and discussed three barriers to understand the culture of the Indian subcontinent. Language was the first barrier as the languages of the subcontinent were Sanskrit, Pali and Prakrit. The travellers understood Persian and Arabic. The second barrier was the difference in religious beliefs and practices. The third barrier was the self-absorption and consequent insularity of the local population.