Peter needs to speak to his supervisor before they sit in on a client call in about an hour

Peter's office is down the hall from his supervisor's office and he's not sure how tight his supervisor's schedule is and whether he has time to talk things over. There are a few controversial issues to be discussed on the call and Peter is anxious to learn his supervisor's point of view on these issues. Which form of communication would be the best way for Peter to communicate with his supervisor: instant messaging, a face-to-face chat, or email? Explain your answer.

Normally an email or an instant message might be more appropriate, depending on how busy his supervisor is, but Peter needs to use a form of communication that provides instant feedback. With written communication like email or even instant messaging, Peter has no control over when his boss will read his message, and it may take more time that Peter can afford. Face-to-face communication will also allow him to take into account the "unspoken" body language and facial expressions.