Harappan archaeology

City drains are structural evidence of how an urban settlement was organised. Their alignment, connections with houses, slope, covering, and outlets can show planning, water management, waste disposal, and concern for sanitation. Option D is correct because drainage belongs to the organisation of an urban centre. Drains alone cannot prove only religious beliefs, war policy, or language knowledge.

Images on seals are visual archaeological evidence. Animal motifs may have represented symbols, identities, religious ideas, groups, or social meanings, although their exact interpretation must remain cautious because the script is not fully understood. Option A is correct because the figures can reveal symbolic and belief-related information. They do not accurately predict rainfall, teach modern languages, or function merely as decoration in every case.

The governing concept is the limitation created by an undeciphered script. Harappan seals contain signs, but historians cannot yet read them with certainty, so the names, language, and precise meanings connected with many inscriptions remain uncertain. Thus, option C is correct. The seals are not modern, they are not necessarily too large, and the claim that they contain no signs directly contradicts the evidence.

The governing concept is comparative archaeological interpretation. When similar objects, designs or production standards occur across several Harappan cities, they may indicate interaction, movement of goods or ideas, and shared cultural practices. The evidence does not prove that every city was identical, but it supports the interpretation in option A. Isolation, absence of trade and modern origin contradict the archaeological context.

The governing idea is standardisation in construction. If bricks retain similar proportions and sizes across structures or successive building phases, this suggests that builders followed established measurements or shared technical conventions. Option C is therefore correct. Such evidence does not prove only religious similarity, the absence of planning, or that every building belonged to a separate period.