The answer to your question is B. stressor.
A stressor is an event or situation that causes a strain on your body or mind.
anger,depression,tired,hungry,anxiety,sad
There are more than 3 million US cases per year
I would say the opening of the play displays dramatic irony. When they are talking about the two households they say something a long the lines of "with their death bury their parents strife" which means only when Juliet and Romeo died did the to households stop fighting. I would say this is dramatic irony because the audience knows that something will happen but the characters do not.