Answer:
The correct answer is seriousness.
Step-by-step explanation:
In the excerpt, we can see that the Friar is talking about the consequences of Romeo and Juliet's love. They loved each other too dearly and were prepared to go to extreme lengths to be together. Unfortunately, their efforts were futile because both of them ended up dead, unable to be happily together.
Friar's speech is very serious - he says how we should do everything moderately, even love others moderately, because only then will we remain happy. There is no excitement or hopefulness in his speech because this is a tragedy and must end on a sad note.