The correct answer is B. Describing what happens during and after a flood
Step-by-step explanation:
A cause-and-effect essay is a type of academical paper mainly written with the purpose of explaining and analyzing the causes or triggers of an event or situation, the event or situation itself and then the consequences or effects the situation or event had. Because of this, topics that are suitable for this type of paper are those that can be explained in terms of cause and effect or triggers and consequences and therefore from the options provided the one that is more suitable for a cause-and-effect essay is "describing what happens during and after a flood" because this topic or instance allows the writer to explore and analyze the causes or triggers and the effects or consequences of an event which is exactly the purpose of cause-and-effect essay.