According to Carneiro's theory of environmental and social circumscription, which of the following ...

According to Carneiro's theory of environmental and social circumscription, which of the following situations would be likely to give rise to civilization?
 
  a. Neolithic villagers first began to expand into the vast interior of central Europe and encountered hostile tribes.
  b. Settlers moved along the Rhone and Rhine, made it to the western coast of Europe, and found themselveshemmed in by the sea and other settlements that had been established.
 c. Seafaring peoples began to populate the Pacific islands.
  d. Paleolithic food foragers first entered the New World.
  e. Neandertal coexisted for years in Europe with H. sapiens and fought over resources.