The action of the speaker that can be considered ironic is that actually the speaker takes initiative of establishing the wall up to himself but then he questions it and has some doubts about that. There is another irony, I would say, the main one, you may find it useful : the wall which was meant to separate neighbours brings them together every year in order to repair it. Is it really the borderline?Hope that helps.
A. Separate
<span>Segregate: to separate or set apart from others or from the main body or <span>group.</span></span>
A. The percentage of sea otters…
Answer:
I would say B. or D. but I need the context of the story to know for sure
