Choose the correct reason and complete the sentence:
The evidence of the first excavations at Harappa had indicated __________
(a) the first settlement of the Early Harappan period was established around 3300 B.C.E
(b) the city of Harappa was divided into two parts – the ‘Citadel’ and the ‘Lower Town’.
(c) internal changes begin to appear in Harappan cities.
(d) the decline of Harappan civilisation.