Which of the Following Was a Distinctive Feature of the Nok

Which of the following was a distinctive feature of the Nok people?

A) They were the only African people to have developed a written language.
B) They created life-sized terra-cotta heads that were likely used in religious rituals.
C) They were one of the few peoples in Africa to not take up iron smelting.
D) They constructed monumental temples similar to the pyramids of Egypt.