I believe the answer is: -The Stamp Act was designed for the colonists to repay the British for the cost of the French and Indian War
In the stampt act, the colonists was required to pay additional tax payment for every paper product sold in their cities. The money that obtained through the increase in taxes would be allocated by the british government to buy additional supplies and weapons for the war.
a) one argument that barton makes in the passage is that historians cannot recreate a new history just because they don't want britain or europe being in the center of world history, and such acts will only vandalize history. The passage talked about 'de-center' Europe from the world history will present many problems, and this meant that we should learn the right history and we shouldn't focusing on making history what we like.
b) one cultural or economic development in the late 20th century that explain the "impending decline of the west" was the decolonization events, which led to many European countries to become less powerful since they cannot get as much money from their colonies anymore like they used to. which led to many new nations with new cultures forming, not the blind triumphalism of the old modernization theory of inevitable progress towards westernization.
c) one cultural or economic change in the late 20th century that historians who supported the process of de-centering world history would cite as a limitation was the soviet union's success in the middle east, which supported barton's argument in the 2nd paragraph where "westernization is inevitable".