Step 1: Understanding the Concept:
The question requires arranging key events in the history of Harappan archaeology in the correct time sequence, from the earliest to the most recent.
Step 2: Detailed Explanation:
Let's establish the dates for each event:
(A) Report of Alexander Cunningham on Harappan seal: Alexander Cunningham, the first Director-General of the Archaeological Survey of India (ASI), visited Harappa and found a unique seal. He published his report on this find in 1875. This is the earliest event on the list.
(C) Daya Ram Sahni begins excavations at Harappa: The first systematic archaeological excavations at Harappa, which led to the discovery of the Indus Valley Civilization, were started by Rai Bahadur Daya Ram Sahni in 1921. This is the next major development.
(B) S.R. Rao begins excavations at Lothal: The excavation of the important Harappan port city of Lothal in Gujarat was led by archaeologist S.R. Rao. This work took place between 1955 and 1960.
(D) Vasant Shinde begins archaeogenetic research at Rakhigarhi: Archaeogenetic research, which involves studying ancient DNA, is a very recent advancement. The significant research on skeletal remains from Rakhigarhi, led by Vasant Shinde, yielded major publications around 2018-2019. This is the most recent event.
Step 3: Final Answer:
The correct chronological order is: Cunningham's report (A), Sahni's excavation (C), Rao's excavation (B), and Shinde's research (D). Therefore, the sequence is (A), (C), (B), (D).