Perhaps all societies (are significantly more advanced) than our own have achieved an effective personal immortality and lose the motivation for interstellar gallivanting, which (may), (for all we know), (be) a typical urge only of adolescent civilizations.

A．That Zimring believes that the death penalty can’t ever be abolished in America even if, in time, a majority of Americans would like it to be.
B．That Zimring is confused and doesn’t know what he thinks.
C．That Zimring is sceptical that it will ever be abolished but maybe it will one day.
D．That Zimring believes that it will eventually be abolished but that the decision will not be easily agreed and when it is it will still be deeply unpopular.