What Do Scientists Mean When They Say That a Flood

Multiple Choice

What do scientists mean when they say that a flood is a 100-year flood?

A) A flood of that magnitude will occur once every 100 years.
B) Every year there is a 1% chance of a flood of a certain magnitude occurring.
C) There isn't enough information to determine how frequently flooding occurs.
D) Every year, there is a 10% chance of a flood of a certain magnitude occurring.
E) The last time a flood of that size occurred was 100 years ago.