Events that make a conflict more difficult are called
causes.
complications.
reactions.
resolutions.

I'd say complications.  It wouldn't be cause because the said conflict is already a problem.  A reaction has nothing to do with the problem getting worse itself.  Resolutions are when the problem is resolved.  I think it would be complications, because it's making the conflict worse than it already was.

Explanation:

there is no passage what do you mean?

give me the passage and i will answer your question

the characters in string all have major secrets that they strive to avoid revealing throughout the play.