I want to know the answer to the following question:
How many races were people asked to mark on the US Census after OMB revised their standards in 1997?
All the background I'm provided with is that "Among the changes, OMB issued the instruction to "mark one or more races" after noting evidence of increasing numbers of interracial children and wanting to capture the diversity in a measurable way and having received requests by people who wanted to be able to acknowledge their or their children's full ancestry rather than identifying with only one group.". Is that enough to answer the question?