The timeline below shows events in both Mesoamerica and South America during the century before the Spanish arrival in the Americas. Use the timeline below to answer the following question: A vertical timeline with the following entries in this order: 1400s Expansion of Aztec empire in Mexico. 1400s Inca empire enters period of expansion. 1426-40 Aztecs at Tenochtitlan form Triple Alliance with neighboring cities of Texcoco and Tlacopan, emperor Itzcoatl reorganizes state to concentrate power in his hands. 1438 Inca emperor Viracocha dies, his successor Pachacuti expands Inca empire north to Ecuador. 1440s Incas build great fortress at Cuzco. 1440-68 Reign of Aztec emperor Moctezuma I, he and his warriors conquer large areas of eastern Mexico, taking many people prisoner. 1450 Inca city of Machu Picchu built on high ridge above Urubamba River in Peru. 1455 Huge temple built to Aztec war god Huitzilopochtli in Tenochtitlan. 1470s Collapse of Chimu culture in northern Peru. 1471-93 Emperor Topa Inca expands Inca empire into Bolivia, Chile, and Argentina. 1473 Tenochtitlan absorbs neighboring Aztec city, Tlatelolco. 1486-1502 Rule of Aztec emperor Ahuitzotl, Aztec empire at height of power in Mexico Which conclusion is supported by the timeline? After Viracocha died, the Inca Empire declined. The expansion of the Aztec Empire caused the Inca Empire to decline. The expansion of the Inca Empire caused the Aztec Empire to decline. After Pachacuti took over, the Inca Empire focused on building projects.