China'sNewFoodActprovidesforafoodrecallsystem_____producershavetostopproduction_____theirfoodisn'tuptostandards．（）A.that；ifB.where；ifC.which；whenD.when；where

　　China's New Food Act provides for a food recall system_____producers have to stop production _____their food isn't up to standards．（）

　　A.that； if

　　B.where； if

　　C.which； when

　　D.when； where