A literal question for this excerpt would be: Who brought a radio-jammer from a head-shop?
The correct answer is D. On the other hand
It shows a contrasting fact.
Parents should have responsibility
D. "She ignored the is he or isn't he debate
D. she felt it was far more important to help the family
I'm not sure Orwell does, or that it matters. You can read this story as a brutal kind of entertainment, and not consider the issue of trust at all. So, that is one option.
If you really want to examine what Orwell does to gain the reader's trust, start with the opening line, where Orwell says he was hated by a lot of people.