Race was asked differently in the Census 2000 in several other ways than previously. Most significantly, respondents were given the option of selecting one or more race categories to indicate racial identities. Data show that nearly seven million Americans identified as members of two or more races. Because of these changes, the Census 2000 data on race are not directly comparable with data from the 1990 census or earlier censuses. Use of caution is therefore recommended when interpreting changes in the racial composition of the US population over time.

Answer this question, if possible (if impossible, reply "unanswerable"): How many race categories were respondents able to select in the Census 2000?
one or more