Monuments (Herostones) for the dead soldiers bearing their names, which

Q. Monuments (Herostones) for the dead soldiers bearing their names, which were erected and worshiped during the Sangam Age, were known as:
(a) Nadukul
(b) Virakkal
(c) Both (a) and (b)
(d) Mahavirakkal
Ans: (c) Both (a) and (b)