B. chief examiner.
A chief examiner would be someone or something else unrelated entirely. Perhaps a police chief or a medical examiner are the closest to a "chief examiner" anything.
Flooding rivers helped contribute to the beginning of farming communities because of sediment deposits that would be spread beyond the banks of the river to the land near rivers. This sediment helped to create highly fertile land that could then be used for farming. The mineral rich sediment helped to develop early farming and allowed for the natural cycle of rivers to boost agricultural production.
<span>C.one that has two chamber than can provide checks on policy making decisions</span>
Yes, it is true that historians believe that the time from prehistory to the development of agriculture spans more than two million years, since it is thought that humans first appeared on Earth roughly six millions years ago.