The answer is C
I hope i helped and got the write answer :P
The navajo tribe has no members that speak english today.
Arnold J. Toynbee (1889 – 1975) was a British and philosopher remembered for his great “Study of History” which is a big work of 12 volumes that analyze 21 civilizations; their rises and falls.
His work is a combination of philosophical and objective thoughts, so this insures the combination of facts that are analyzed from two perspectives, because he is using concrete historical events combined with his philosophical and empirical ideas. That is why many historians, philosophers, sociologists, political scientists are interested in his books and how civilizations emerged, grew, declined and dissolve themselves.
Kids probably needed to work the farm and tend to the livestock, etc. War has a nasty way of disrupting normal life.