Anna is a first-grade student who is learning to sort objects based on single characteristics such as color, size and type. Her teacher gives her directions to create specific groups, for example, “Which of the objects are round?” and “Show me the objects that represent animals.” As she works, Anna starts to make her own groups and is able to identify what characteristics she used to sort the group out. Of the following instruction strategies, which strategy is Anna’s teacher using to help her learn how to make connections and classifications?