Hi Marce,
Let's go back a step to Adam's answer. I'm figuring Adam didn't look at the drill itself and then perhaps misread your question, because I can't figure out why he mentioned context (which isn't at all a part of the drill) or even why this was unclear to him. I'll likely go back and delete his response as I personally find it confusing, and would hate for anyone else to be confused by it too.
The happy news here is that there is no error here. When you are asked to explain something, that falls into the Resolve category. We consistently classify these questions in this manner because they are most often connected to something inexplicable (such as a paradox) that then requires an explanation that helps it all make sense.
As is often the case in these books, I purposefully foreshadow ideas early in the books that are then later discussed in greater detail. In this case, you can see on Page 384—in the Resolve chapter—that "explain" is right there on the list of key words often used in Resolve question stems.
As for errors Marce, I'm well-known to be a very straight shooter if I think something could be clearer or is in fact incorrect. That's not the case here, fortunately
But please advise me where your other problem was, since I'm not aware of you finding another error.
While I work hard to answer as many questions as I can here, I cannot get to every one (and actually prefer that staff let me take the hardest ones). I'm happy to review anything you think is problematic, though. The great news is that with the vast majority of initial concerns that something is wrong, they are in fact correct.
Thanks!