Which of the following was a direct cause of job specialization in early human civilizations?
a. improvement of hunting methods.
b. development of agriculture.
c. stratification of society.
d. establishment of trade networks

Which of the following was a direct cause of job specialization in early human civilizations?A. Improvement of hunting methods. 
B. Development of agriculture.
C. Stratification of society.
D. Establishment of trade networks  
THE ANSERW IS B