Which of these scenarios demonstrates an early form of social stratification?
a. a tribe comes into conflict with its neighbor over a water supply.
b. a farmer trades some of his crops to another farmer for different crops.
c. a hunter shares his meat with members of his tribe.
d. a strong warrior is selected as a leader of a group.

your answer would be D. A strong warrior is selected as a leader of a group

the captain of a steam ship naturally chooses the shortest route to his destination. since a sailing ship is usually pushed by winds and currents, its captain must find a route where the wind will probably blow in the right direction. tacking, i.e. using contrary wind to pull (sic) the sails, was always possible but wasted time because of the zigzagging required, and this would significantly delay long voyages. the early european explorers were not only looking for new lands. they also had to discover the pattern of winds and currents that would carry them where they wanted to go. during the age of sail winds and currents determined trade routes and therefore influenced european imperialism and modern political geography. for an outline to the main wind systems see global wind patterns.

pilotage or cabotage, in one sense, is the art of sailing along the coast using known landmarks. navigation, in one sense, is the art of sailing long distances out of sight of land.[1] although the polynesians were able to sail the pacific (with great difficulty) and people regularly sailed north and south across the mediterranean, before the time of columbus nearly all sailing was coastal pilotage

        it is some were in here? ///

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.