The correct answer is B.
The emergence of agriculture and the beginning of sedentary settlements and civilizations, constituted the start of the Neolithic period of human history. It meant the end of nomadic lifestyles in which humans could only rely on hunting, fishing and gathering for food collection.
Agriculture and sedentarism came together with specialization and division of labor. Specialization allowed to improve the instruments and tools used for each activity and productivity was rapidly enhanced. For the first time in history, men produced more than they could consume and trade started to happen.
With the growth of industrialization, many countries in Europe experience an increase of wealth. This also led to competition among European countries. They saw a need to protect their interest and with that they began to strengthen their military and this led to formation of alliances. As competition became more intense it affected political affairs as well which later lead to war.
A major difference between the introduction and conclusion paragraphs in an essay is the structure of those paragraphs. The introductory paragraph has the thesis statement, the hook, and the position of the essay. In the conclusion essay, the structure includes the restatement of the thesis, including the position, and then the call to action if the essay is persuasive, which is the sort of rallying point to get others mostly the readers to back your perspective