Despite getting the highest marks on a recent study by nonprofit think tank the Brookings Institution, Education Secretary Betsy DeVos targeted Denver Public Schools Wednesday, claiming the district doesn’t offer enough school choice.

This prompted Denver Public Schools Superintendent Tom Boasberg to fire back, saying he “respectfully disagrees” and that the district does not support private school vouchers.

“We believe that public dollars should be used for public schools that are open to all kids, whether they are district-run or charter,” the statement read.

DeVos’ comments came at a Brookings Institute event, where the think tank announced for the second year in a row, it had ranked Denver Public Schools as its top school choice system.

The ranking is based in part off the district’s access to education and resources.

DeVos said Denver is an example of a district that appears to give families the option to pick their schools, but actually doesn’t have enough school choice options, such as private school vouchers to parents.

 “Denver scored well because of the single application process for both charter and traditional public schools, as well as a website that allows parents to make side-by-side comparisons of schools,” DeVos said. “But the simple process masks the limited choices there.”

She went on to say that, “even though a district may place well on the competition index, the letter grade does not necessarily reflect the state of education within that district. The benefits of making options accessible are canceled out when you don’t have a full menu of options.”

DeVos praised New Orleans schools – which came in at No. 2 in the rankings – for providing vouchers for low-income students to attend charter schools. She says the district’s “sophisticated matching system maximizes parental preference and school assessment.”

The Washington Post reports what makes DeVos’ comments unusual is that education secretaries don’t typically single out single districts when it comes to criticism.

““A core principle in Denver and one of the main reasons we rank no. 1 nationally in school choice is that we ensure equitable systems of enrollment among district-run and charter schools, where all schools play by the same enrollment rules and all schools are subject to the same rigorous accountability system,” Boasberg’s statement read. “We do not support choice without accountability.”

You can find the rankings and methodology from the Brookings Institute here: http://brook.gs/2oiT8mb