A major significance is that the Ona-Agbadi relationship leads to the birth of the heroine, Nnu-Ego.  It also brings out the cultural setting of the novel.  Despite the mutual love between the couple they can not be married in the interest of
Ona’s father who does not have an heir to succeed him, this makes Ona to be a mistress to Agbadi and the product of the relationship belongs to Ona’s father or Agbadi depending on the sex of the child.

This question was shunned by most candidates.