Which of the following is correct
(i) Coins as a medium of exchange were introduced for the first time in the Sangam Age.
(ii) Prakrit was the language used by the common people in Northern India during the Mauryan period.
(iii) Vienna Papyrus, a Roman document, mentions trade related to Muziri.
(iv) The concept of Thinai is presented in the Tamil grammar work of Pathupaattu.