No because it’s not supposed to be capital if it’s not an acronym
Its the second answer
"it causes the bride to blush and makes her content"
as indicated by "she looked bashfully down; The pride o' her heart was beguiled" (beguiled means to charm aka make content)
To tell the reader how the bike has been a part of the persons life but realised that it has changed the way they look at things. I hope this helps.
I would say relative pronouns