The correct option is B People of this civilization had the knowledge of iron.
Mayan people were not familiar with the use of iron metal. Mayan smiths worked primarily in copper during the initial period, with some low-arsenic alloys, as well as occasional use of silver and gold. The Maya used stone tools fabricated from chert and obsidian instead of iron tools. The unawareness of Mayas about the Iron metal can be attributed to the lack of available iron ore in their geographical domain.