Who were Umnars during Sangam Age?
Megalithic monuments refer to the monuments made up of large stones. However, not all monuments constructed out of large stones are megalithic. Different types of iron tools have been discovered from megalithic monuments. They include a sword, spear, knife, book, lamp, nail and so on. Hence, this period is known as the Iron age in South Indian History.
Thus, the correct answer is D.