What is the formal name of the flag, featuring a green-white-red tricolour with an eagle perched on a cactus devouring a serpent in the centre?

• A Estandarte Nacional
• B Pabellon Patrio
• C Ensenada Oficial
• D Bandera Nacional ✓

The central emblem references the Aztec legend of the founding of Tenochtitlan, where an eagle on a cactus signalled the chosen site.