The inca produced a magnificent, expansive, and complex culture, despite lacking all of the following except
a. a system of writing
c. steel weapons
b. the wheel
d. a system of record keeping

b. the wheel

There are several Inca features that were different from normal human beings from other areas of the globe. The speciality was the Inca head, since it was larger than normal in size and also were kept bald to display their cranial mass.The Inca mostly kept their head shaved and it continued generation wise. The Inca, specially the Sapa Inca had a very pronounced nose to go along with their huge head. Most of the early Inca got murdered by Atahullpa just prior to the conquest by the Spanish. The Sapa Inca was considered the pure Inca as they only had children from their full blooded sisters to keep the gene intact.