George places into service a residential rental building in 1998 and elects to depreciate it over 40 years using the straight-line method. When George places another residential rental building into service in 1998, he may depreciate it over __________ years using the straight-line method.

a) 15 or 27.5

b) 27.5 or 39

c) 27.5 or 40

d) 39 or 40