Read the passage. Archaeologists examined terraces built into hillsides near an ancient village. Soil caught behind the terrace walls showed less erosion than exposed slopes nearby. The village also had stone drainage channels that diverted runoff away from houses. Researchers sketched the terraces and measured the depth of soil layers. The writer makes this claim: Terraces may have reduced erosion, but other water-management features also shaped the village landscape. Which quotation best accounts for the uncertainty, exception, or competing explanation in the claim?