The development of crop cultivation makes specialization of labor possible because

The development of crop cultivation makes specialization of labor possible because
 
  a. there is little need for more technology.
  b. group intelligence improves with a cereal-based diet.
  c. since farming is more efficient than food collecting, more people can be freed to engage in an activity other than food production.
  d. the extra time generated by more efficient technology allows people to go to school and learn much more complex trades.
  e. the trade that results from all forms of crop cultivation motivates societies to specialize in order to control the market.