I believe this line means exactly what is says - the parents did everything in their power to do what they had to do. I'm not really sure about the context of the sentence, or where it is from, but I'd say that the parents tried hard to achieve what had to be done, and they did everything they knew how to do in order to achieve it.
The narrator compares Juan with the basket of his letters. They are the reflection of his work. He is fully devoted to it, but at first, he was against censorship and tried to work around it and he does it in a cunning way. He ends up liking it to the point of being obsessed.
I'm pretty sure it's B.) situational irony.
A hook is something that makes a sentence interested and compels the readers to continue reading the text - it hooks them so they have to know what happens next.
Having this in mind, the hook in this text would be the sentence A. For the first time in decades, Baby Boomers have been outnumbered by another group - the Millennials.