1. In the UK, HDG is the normal selection. (But I think they are looking for B). FWIW, the use of VNAV on its own is generally not recommended. And on an Embraer E jet, I wouldn't use VNAV at all because it's pants.
2. What a crap question, it is too type and version specific.
3. Again, a type specific question, but A would probably be the best answer.
If I was asked these questions in an exam, I would refuse too answer them as they are too type and version specific.