Remember that even though the PMP Exam is largely based on the PMI's PMBOK Guide you should not only know all of the concepts from here, but you must be able to analyze and answer the situational exam questions with a combination of practical project management knowledge and with what the PMBOK Guide says. Generally speaking, going against PMI principles is never a good option. At least not during the PMP Exam. It is also better to choose the ethical option even though they may seem to be the tougher choice.