In urban areas, there are more people, therefore not a lot of farmland. (that eliminates C) If city buildings don't allow flood waters to recede, that could be dangerous in many ways. (So A is still a reasonable answer) If most cities are built in flood zones, there should be some form of shelter if houses aren't safe. Pollutants and diseases being carried in water are already dangerous, but easier to spread with rapid flood waters that are sweeping everywhere. So your best answer would be either A or B.
To address problems caused by the dissolution of the Soviet Union some Eastern European nations privatized industry, increased foreign investment, and joined the European Union.
So answers are A), B), and E).
Answer: B, this is because higher luminosity white dwarfs will be in the B spectrum white dwarf category.
