Passage Summary: An archaeologist thinks a certain building wasn't a house because it was built with fancy imported stones, while the known houses in the area only used local rocks.

Conclusion: The specific ancient stone building being investigated was likely not used as a residence.

Reasoning: The building contains non-local quartz and granite, whereas most other buildings from that era that served as dwellings were made exclusively of local limestone.

Analysis: The argument relies on the assumption that the materials used in a building are a reliable indicator of its function. To strengthen this, we need to bolster the link between 'local limestone' and 'dwellings' or 'imported stone' and 'non-dwellings.' Look for an answer that suggests a strict pattern, such as evidence that non-residential buildings in this culture were the only ones to utilize quartz or granite. The more we can isolate imported stone as a feature of non-dwellings, the stronger the conclusion becomes.