The different types of rock music have been popularised by the American film and music industry during the 1980's to a point that it spread out throughout the world. The trend was attracted internationally because of the high American standards of music incorporating the most advanced technologies.
I think it is B because they had fertile farmland
Islamic armies conquered major cities to help spread islam on three continents.
The right answer is: he worried they would overrun government elections. :)
The economy was largely based on agriculture