Cage (Situational Irony)
Although America compares her experience living in the palace to being in a cage, she comes to understand this time as freeing in many aspects, as it is the only place where she can be honest about what she wants, and pursue those desires. Because America's life is so restricted when subject to the caste system, it is that which cages her as a Selected which also sets her free from the demands of her previous life. This is an instance of situational irony, as America's realization about her freedom is a plot twist in a narrative of reluctance and struggle in the palace.
Wonderful (Verbal Irony)
America's internal dialogue is ripe with instances of sarcasm, as demonstrated on p. 57 when she mentions that she had to worry about rebel attacks once she was Selected, even though she was not yet at the palace. America wryly calls this new status "wonderful." Sarcasm is an example of verbal irony.
Someone to love (Dramatic Irony)
When America tells Maxon about her history with Aspen, she says that she hopes that he will one day "find someone you can't live without," and that she hopes he will "never have to know what it's like to have to try and live without them" (195). This is a moment of dramatic irony, because even though America believes that she is giving sound advice, she does not realize that the person Maxon loves and is facing the possibility of living without is her.
America's smile (Dramatic Irony)
Right before America sits to have her photo taken as she submits her profile for the Selection, she learns that Aspen has been saving money for their eventual marriage. This knowledge causes America so much happiness that she smiles beautifully for the photograph, and it is this smile that eventually causes her to be chosen, as her photo is particularly beautiful. This, in turn, makes her marriage to Aspen less likely. This is an instance of dramatic irony, as America understands her situation to be vastly different than it actually is.