The civilization located in the area labeled A was the Aztec civilization. The Option B.
The Aztecs also known as the Mexica were a Mesoamerican civilization that thrived in the region of modern-day Mexico from the 14th to the 16th century. They established their capital city called Tenochtitlán, in the heart of the Mexican highlands which corresponds to area A on historical maps.
The Aztecs were renowned for their advanced agriculture, impressive city planning, and intricate social and religious structures. They worshipped a pantheon of gods with Huitzilopochtli (the god of war) being one of their most significant deities.
The Aztecs are best known for their downfall in 1521 when Spanish conquistadors, led by Hernán Cortés that overthrew their empire.