Your preferred response to stuttering?

Your preferred response to stuttering? I was at a grocery check out today what I heard the bagger say something. "What was that?" He responds fairly incoherently, stuttering (again, I realize). From the situation and the number of syllables he used, I don't have trouble guessing before he tries again: "Paper or plastic? Plastic is good," I reply. I'm sure every person will be different, but I was curious about your preferences. Would you rather me wait until you've gotten your phrase out? Or would you like me to respond without repeating what I believe you're trying to say? Or repeat/rephrase (as above) and answer? **Edit-** I appreciate all the responses, so I'll just reply up top. It's (of course) a mix of preferences, but the way each of your frame your situations is very helpful in understanding how different actions are appreciated in different contexts.