Step 1: Recall each site's defining feature: Harappa (1921, Daya Ram Sahni) was the first Harappan site discovered. Kalibangan (Rajasthan) is famous for the evidence of a ploughed field found in its pre-Harappan levels. Chanhudaro is the only major IVC site without a citadel and is known as a centre of craft/bead production. Dholavira (Gujarat) yielded a large inscribed signboard, sometimes described as an old notice board.
Step 2: Match and pick: a-Harappa=(iv) first discovered site; b-Kalibanga=(iii) ploughed field; c-Chanhudaro=(i) craft production; d-Dholavira=(ii) old notice board ⇒ option (B).
Final Answer: a-(iv), b-(iii), c-(i), d-(ii)