How might the trail of tears actually have saved the peoples of the “five civilized tribes” from complete demise?

The trail of Tears forced the tribes to move, allowing a small portion to move to land were the population could go and restart. Whereas if there was no trail, and the tribes stayed where the were, this would have potentially led to more war between the colonists and the Native Americans, leading to the possible decimation of the "Five Civilized Tribes". Good luck.

the answer is a. the harappan civilisation is also called the indus valley civilisation, this is because they built their cities along the indus river. the reason behind this location can be found in the rest of the "old world" civilisations like mesopotamia or egypt, the first built their cities along the rivers tigris and euphrates, the second along the nil; : their respective civilisations thrived because the overflowing of their respective rivers produced favorable conditions for agriculture, their main support.