Based on the text, it can most reasonably be inferred that the material composition of andenes contributed to agricultu…

To determine how the material composition of andenes contributed to agricultural viability, two key parts of the text must be synthesized: the specific environmental obstacle described in the opening and the thermal behavior of the stones described in the second half. The passage notes that nighttime frosts rupture plant cell walls even during seasons when daytime temperatures are mild enough for farming. It then explains that the dark volcanic stones chosen for the terrace walls possess high thermal mass, allowing them to absorb solar energy during the day and re-radiate that heat into the soil and surrounding air after dusk, elevating night temperatures relative to untamed slopes. Connecting these points leads to the inference in Choice A: the stones functioned to temper overnight cold, protecting crops from tissue-destroying frosts during an otherwise viable growing season.

Choice B is incorrect because it reverses the protective relationship described in the passage; the text discusses the walls thermally protecting the crops, not soil or runoff protecting the stones from frost damage.

Choice C is incorrect because it misattributes the timing of the thermal benefit; the passage states that daytime temperatures were already hospitable and that the stones released their heat after dusk, not that they raised daytime temperatures to shorten seasonal cycles.

Choice D is incorrect because it misinterprets solar absorption as a shading or shielding mechanism against daytime radiation, whereas the text identifies it as an energy-storage mechanism meant to counteract nocturnal cold.