Thanks, both responses seem to reflect the majority opinion, however, neither (nor any other information I have found to date) address my basic question ... Are they asking who filled out the form or who is responsible seeing that the form is prepared.
I believe that a literal reading of the instructions would suggest that they want to know who has the responsibility, but I suspect that they really want to know who filled out the form.
The responses so far would suggest that others have been assuming that they want the latter, but I'm not sure that the instructions support that.