When Do Extremist Parties Tend to Rise

When do extremist parties tend to rise?

A) In periods of great national struggle, such as high unemployment, as people tend to become more risk-takers than risk-adverse if they see that they are losing.
B) In times where the status quo is the most popular, since they are likely to be corrupted soon after.
C) When a large effort is made by people to vote for the candidate they agree with most, not necessarily the one they think has the best chance of winning.
D) They are only popular when a country is preparing for war or in the middle of it.