△DEF is reflected to form​​ ​ △D′E′F′ ​. The vertices of ​ ​ △DEF ​ ​ are ​ D(−1,−1) ​ , ​ E′(1,−1) ​ , and ​ F(−1,−6) ​ . The vertices of ​ △P′Q′R′ ​ are D′(−1,1) , E′(1,1) , and F′(−1,6) . Which reflection results in the transformation of ​ ​ ​ △DEF ​ ​ ​​ to ​ ​ ​ △D′E′F′ ​ ​ ​​? reflection across the x-axis reflection across the y-axis reflection across y = x reflection across y=−x