Concept:Architectural uniformity across Harappan sites like Dholavira and Mohenjodaro indicates strong coordination, likely stemming from a mix of central authority, local adherence to cultural norms, and active trade networks.Explanation:The uniformity suggests a central authority set broad planning guidelines for all regions. Local rulers then followed these cultural blueprints while managing local affairs. Frequent communication and organized trade between cities helped share building techniques and maintain consistency. There is little evidence of military force being used to enforce this uniformity; instead, economic and cultural factors drove it. Thus, statements 1 (centralized authority), 2 (local rulers following blueprint), and 3 (communication/trade) are supported. Statement 4 (military dominance) is not supported.Answer:Option B: 1, 2, and 3 only