The name of this period is the (First) Industrial Revolution. It started in Great Britain in the middle 16th century as it was here where the technological innovations that triggered the whole proccess were started. It lasted until 1820s-1830s in GB but it was also consistently spread to other European countries. Most countries ended up experiencing this same process but at different speeds, depending on the kind of economy they had before.
Less people were required to produce agricultural goods due to new machinery and innovations. These people moved from rural areas to cities where they could find opportunities for different types of unskilled industrial work. Also the craftery was substituted by industrial type of production, where goods were elaborated in chain and such type of production did not require artist skills, but only to understand how the machine worked. This is how all unskilled workers from rural areas could find jobs in the new urban and industrial production system.
Moreover, the whole process was fostered by the great amount of raw materials coming from the colonies that European countries had all over the world and that were transformed into goods in the factories.
Finally, technological innovations go hand in hand with scientific development and to the extension of human knowledge about the world.
The reason why it takes a long time to ratify the Articles of Confederation is that U.S. just declared independent from Britain, in other words, they just passed the Declaration of Independence, and in order to keep a country on track, they need some sorts of form of government, and they don't want to repeating the history, or have another tyrant, or a king, to rule over them again, which is a part of reason why they declared independent (the actual reasons is the king taxes us for no reason and we can't participate in the government), so they need all of the 13 states to approve, or sign, the Articles of Confederation, majority of them signed it, some of them having issues about the rights in the Articles of Confederation, so someone, I forgot his name, promised to includes all of the rights into the Articles of Confederation, which they can't do it instantly, which later known as the Bill of Rights (the first 10 amendments), so it takes longer to get the whole Articles of Confederation to be approved, or ratified.
Hope this help, my English is not that well so please excuse for it.
I'm at least 85% sure that the answer would be A, it seems like the most secure answer to give.
