3. Ellen Baker knew that her new job in a middle school would require that she understand differentiated instruction. Using this strategy, her students would be more apt to progress and master the concepts they needed to succeed throughout their school years. One of the techniques she decided to use involved grouping students by their learning needs. She would group students who had scored poorly on their fractions tests with similar students to remediate and develop that skill. She likened this type of differentiated instruction to having students continually work in their zone of proximal development. The type of strategy Ellen Baker wants to use is referred to as which one of the following?

A. Flexible grouping B. Jigsaw C. Collaborative group work D. Peer tutoring