"Whom" is a relative pronoun
Answer:
How do we know Odysseus is telling the truth when he relates his story to the Phaeacians? He has a trinket given to him from Calypso. We don't; we have to take his word for it.
The first prediction is extremely unlikely. Daniela is described as a "smart and sweet-faced girl" which would make no sense if she somehow behaved "spitefully toward him [Danny]". I can only see the second prediction happening if this were a cheesy cliche romance novel. However, logically this cannot happen, as Daniela was shy and joined no clubs, which limits her ability to gain friends. It would be unlikely if they ever met. Therefore, the prediction that would most likely happen would be the third one. It cannot be the fourth one as Danny has "good humor" and has a nice personality; he would not dislike Daniela with this type of attitude.
The answer is that Danny and Daniela will never meet and become friends.