Answer:
debate
Step-by-step explanation:
In the sentence
When tragedy causes sadness -opposition will causes debate.
An analogy is a relationship between opposition and debate, since comparing an idea like opposition to debate shows that they are related in that a debate requires people to have opposite opinions or stands that on a topic that is in the debate.
Here the premise is that reading tragedy to sadness first shows a similarity relationship
therefore the other options are left behind, and if A tragedy causes sadness then opposition causes debate.