Which of the following teachers uses a constructivist approach in instructional planning?

1) Mrs. Akita gave a pretest to determine the amount of background knowledge she needed to incorporate in her unit about two-step equations.
2) Ms. Levi combined suggested activities from her teacher's manual with activities suggested by peer teachers as the basis for her lesson about the different types of erosion in her state.
3) Mr. Hargrove reviewed several resources identified in his teacher's manual and developed a lesson about the first walk on the moon.
4) Mr. Anthony and his students discussed their unit about crustaceans and decided to create centers that integrated science knowledge, writing skills, and vocabulary.