Which among the following is correct with respect to the Harappan civilization? 1. Ploughing was known to the Harappan people. 2. Fortification was found at all the sites associated with Harappan Civilization. 3. Northern black polished ware type of pottery was found in Harappansettlements. Select the correct answer from the options given below.

Kalibangan in Rajasthan has given one of the earliest evidences (c. 2800 BC) ploughed agricultural fields ever revealed through an excavation. While fortification is found in most of the sites of Harappan civilization, there have been a few sites where no evidence of fortification has been found. Chanhudaro in Sindh is one such example. Red and Black pottery type is found in Harappan settlements mostly. Northern Black Polished Ware is associated with urban Iron Age Indian culture of the Indian Subcontinent, lasting c. 700-200 BCE succeeding the Painted Grey Ware culture and Black and red ware culture. It developed beginning around 700 BCE, in the late Vedic period.