Archaeologists working in the Andes Mountains recently excavated a buried 4, 000-year-old temple containing structures that align with a stone carving on a distant hill to indicate the direction of the rising sun at the summer solstice. Alignments in the temple were also found to point toward the position, at the summer solstice, of a constellation known in Andean culture as the Fox. Since the local mythology represents the fox as teaching people how to cultivate and irrigate plants, the ancient Andeans may have built the temple as a religious representation of the fox. Which of the following is an assumption on which the argument is based? ['In the region around the temple, the summer solstice marks the time for planting.', 'The constellation known as the Fox has the same position at the summer solstice as it did 4, 000 years ago.', 'Other structural alignments at the temple point to further constellations with agricultural significance.', 'The temple was protected from looters by dirt and debris built up over thousands of years.']