Definition of "should" and "can"

Dear Colleagues,

As part of a preparation for PSM I and PSPO I exams I'm going through different practice exams (like Lapshin or Volkerdon) and most of the time I get an incorrect answer on questions where "should" or "can" are used (FYI I'm not a native speaker). Let have 2 examples:

1. Question: The Product Owner and Scrum Master should not be part of the Development Team. (Answers: True or False). Correct answer (according to Volkerdon) is False.