solitude-isolation
jocund-happy
Isolation, while being the closest synonym to solitude, has a negative connotation. As if the writer didn't choose to be alone in bliss, but were rather trapped where they were- alone.
Happy is a commonly used word. It makes the writer/author seem elementary in their writing, which wouldn't fit in this poem as it's a high level poem that can be used for scholarly analysis.
The answer on apex would be " the topic that the speaker has chosen "
C i think, hope this helps
She clearly felt sad to see this day end.
