The correct answer is 2) Inca gold.
The legend not investigated in North America was the Inca gold.
History is full of legends and myths. One of the most famous legends in the Hispanic world was the City of Gold in Peru, Inca Gold, or el Dorado. In 1537, Spanish conqueror Francisco Pizarro kidnaped Inca leader Atahualpa. Spaniards wanted ransom and when the Incas carried the gold to pay the ransom they realized that Atahualpa had been killed and an Inca warrior named Quinaran hid the treasure. The Spanish had seen the golden bars and knew that there was so much gold in the region. That was the beginning of the legend.