C because the plates a sliding past each other
A biome is an area classified according to the species that live in that location. Temperature range, soil type, and the amount of light and water are unique to a particular place and form the niches for specific species allowing scientists to define the biome.
To change the equation, you'd have to take the square root of both sides. When you do this, x^2 cancels out leaving you with x = sqrt(y)
If you need help on the other ones, all you have to do is solve for x by using either addition/subtraction or dividing/multiplying.
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.