How did language spread from one proto-indo-european language to more than 6,000 languages we speak today?

We can thank geography for that. If you look at a map of Eurasia, you can see many massive mountain ranges and rivers, all of which separate early tribes apart. When one tribe is split apart for long enough, the people in each tribe develop their own distinct and unique identity, which also includes languages. There are several very interesting researches on this phenomenon online if you look deep enough and I do recommend you check them out, it's quite the fascinating read.

the correct answer is: (1) affected by gerrymandering; (2) not affected by gerrymandering.

gerrymandering is known as a practice that intends to establish a some kind of political advantage for a particular party or group. to do this district boundaries are manipulated. the new resulting district is named a gerrymandering.

in other words, what gerrymandering does is to draw the boundaries of electoral districts trying to benefit the party who is doing it. sometimes, the party controlling the legislature will redraw it so they can maximize the number of districts they are likely to control.