The overall tone is B) distressful.
Explanation:
In Lord Byron's Poem "When We Two Parted", the speaker is describing the way he feels after a breakup. Since other people don't know about this previous relationship, they mention his loved one's name, and that causes the speaker great pain. His tone is sad; he employs words that indicate he laments having lost that other person, such as "rue", "grieve", "silence", and "tears". He believes he woudn't even be able to greet the other person without crying if they were to meet again someday.