In upgrading Ubuntu using terminal, one may be confronted with questions concerning the removal of obsolete packages or whether one wants to keep current version of some file. The answer options for these questions are
Continue [yN] Details [d]d
d for details, one receives a list of such, which may be advanced using the enter key. The list will end with a line saying
(END), after which one cannot advance further with the enter key.
From this point, how does one return to the upgrade process with out terminating it?