You will be given a definition of a task first, then some input of the task.
This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: Multiracial people who wanted to acknowledge their full heritage won a victory of sorts in 1997, when the Office of Management and Budget (OMB) changed the federal regulation of racial categories to permit multiple responses. This resulted in a change to the 2000 United States Census, which allowed participants to select more than one of the six available categories, which were, in brief: "White," "Black or African American," "Asian," "American Indian or Alaskan Native," "Native Hawaiian or other Pacific Islander," and "Other." Further details are given in the article: Race (U.S. census). The OMB made its directive mandatory for all government forms by 2003.
Output:
When did the OMB change federal regulations of racial categories to bar multiple responses?