Identify the 'barriers' which obstructed the understanding of Al-Biruni regarding the Indian subcontinent: (A) Sanskrit was so different from Arabic and Persian that ideas and concepts could not be easily translated from one language into another. (B) The difference in religious beliefs and practices. (C) The self-absorption and consequent insularity of the local population. (D) Al-Biruni's interest in Indian society. Choose the correct answer from the options given below: