Correct Answer: (c) Joshimath, Dwarka, Puri, Sringeri
Note: Shankaracharya also named as Shankara was born in Kaladi, a small village in Kerala in the 8ᵗʰ century. At this time, Hinduism which had diminished in status due to arrival of Jainism and Buddhism again rose to eminence with the emergence of Shankaracharya. He advocated the greatness of the Vedanta. To study and compile the Vedas, he travelled all over India on foot. His philosophy is known as Advaita Vedanta. The four religious centres established by Shankaracharya are considered as the most important centres of Hinduism. The which indicates that it was imposed in Gujarat and Malwa region. Since it was forced labour in lieu of tas, it was not wage labour. Wage labour existed in ancient India, but it was not called Vishti. Vishti could be imposed on anyone, not in particular on eldest son only.