Story highlights Trump's education secretary speaks at a pro-school choice conference in Indianapolis

She provides no details of the administration's plans

(CNN) Education Secretary Betsy DeVos sharply criticized opponents of school choice on Monday, calling them "flat Earthers" who have "chilled creativity" and held American students back.

DeVos provided no details of the administration's plans to promote school choice, an expansive term that includes expanding access to and promoting less-traditional education options, like charter schools or voucher systems. But she did say states that resist school choice innovations would be making a "terrible mistake."

"They will be hurting the children and families who can least afford it. If politicians in a state block education choice, it means those politicians do not support equal opportunity for all kids," DeVos said.

She told attendees at a pro-school choice conference in Indianapolis that it is important to provide not only options in education, but also "the widest number of quality options."

"If a menu is full of bad options, then do you really have a choice at all?" she said.

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