Igloos did not need to last long. Hunting conditions forced Eskimos to move often, abandoning their old igloos and building new ones. An igloo was used for an average of one month, but it usually could be made to last as long as it was needed. It did not take long to build and gave excellent protection from a hostile climate while it lasted. Igloos were________.
A.affordable
B.collapsible
C.comfortable
D. functional