Explain the theme love vs friendship in the book matched by Allie condie

Love -vs- friendship is a major theme in Matched. Here you have a young girl going to her first banquet knowing that her future husband will be shown to her that night. But wait...... there's a problem. Society messed up somewhere, and they've decided that unlike every other girl, Cassia has two matches. Everyone else has been matched based on information stored on microchips; they've all socialized and have their lives mapped out at only seventeen; they're all certain of their matches, but Cassia gets a wrench thrown into the works.

So what is Cassia to do? She has two matches and may have to make this HUGE decision all by herself. Will it be love based on friendship (Xander is a match and her best friend), or will it be love based on passion and infatuation (what she feels for Kai). Better yet, will she go for the rebellion and choose Kai simply because society doesn't accept him, and he's actually a "forbidden" match. Will love (passion and romance) beat out the unconditional love of the one person who knows her better than anyone?