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.
The answer is False. Majority of the countries that produces large quantities of crude oil are found from the Persian Gulf and are in the Middle East. These crude oil producing countries are Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Aradia and United Arab of Emirates.