When completing a survey it may be necessary to rank some responses and then question each of those responses. This means that returning to the lead question becomes conditional on other responses having already been made. Therefore in the example If the user chose A as the first option, returning to the question would leave only options B, C and D (i.e conditional responses available since one response has already been selected). This would avoid having to duplicate questions, and would make the results far easier to analyse in Excel. It would also mean that hierarchical analysis could be accomplished, based on user responses.
Obviously, in the example given there has to be an "out" option and this would then bypass the hierarchy and move to the next appropriate question.