Terracotta models of plough are an important archaeological find that provide insights into the agricultural practices of the Harappan civilization. Such models have been discovered at Banawali (in present-day Haryana, India) and Cholistan (in present-day Pakistan), indicating the presence of organized farming and use of plough-based agriculture.
Banawali was a significant Harappan site known for both pre-Harappan and Harappan layers, and it yielded various agricultural tools including terracotta ploughs. Similarly, the Cholistan region, which has numerous Harappan settlements, has also produced similar artifacts. These findings suggest that farming using ploughs was likely a known technique among the Harappans.
Options (A), (B), and (D) are incorrect as there is no substantial evidence of plough models discovered at those sites. Kalibangan did show signs of ploughed fields but not terracotta models.