Attirampakkam is a significant prehistoric site where archaeologists have discovered:

Acheulean stone tools
Ancient pottery
Bronze sculptures
Rock-cut temples

The correct answer is: a) Acheulean stone tools.

Attirapakkam is a prehistoric site in the state of Tamil Nadu, India. It is located on the banks of the Palar River, about 100 kilometers from Chennai. The site has been dated to the Lower Paleolithic period, and it is one of the most important Acheulean sites in India.

Acheulean stone tools are a type of stone tool that was first made by early humans during the Lower Paleolithic period. They are characterized by their large size and their distinctive bifacial flaking technique. Acheulean tools were used for a variety of purposes, including hunting, butchering, and woodworking.

Attirapakkam is a significant site because it provides evidence of the early human occupation of India. The site has yielded a large number of Acheulean stone tools, as well as other artifacts such as animal bones and plant remains. These finds provide valuable insights into the lives of early humans in India.

The other options are incorrect because they are not associated with the Lower Paleolithic period. Ancient pottery is typically associated with the Neolithic period, while bronze sculptures and rock-cut temples are typically associated with the Iron Age.