The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
Even though the Aztecs have no metal weapons, they have a resource even more deadly. What is this resource?
Answer:
That resource was sharp obsidian blades, a very powerful rock that could mortally wound the enemy.
Aztecas were known to be fierce warriors. Indeed, since childhood, boys were introduced into the art of war. They were trained by expert warriors.
Aztecs had powerful weapons for their time. They had spears, clubs, and darts. They included the obsidian blades in the clubs to make them more dangerous and mortal.