Because his father has been ordered to relocate on the orders of the Fury (the Fuhrer, Adolph Hitler). Essentially, Bruno's father has been promoted to a Commandant position at Auschwitz, and this is why the family has to leave their house in Berlin.
They are talking about how things in life arent fair and that you should deal with it. For example Two-Bit says "Like it or Lump it' basically meaning to deal with it or get angry about it.
A, In Fact, studies by scientists have found......
In fact followed up by an actual factually proven statement!
He becomes interested in ensuring ....
D. It's very vague. isn't as articulate as the others