. Anthony proposed an experiment during which he would test the friction created when a skateboard is rolled along a flat surfac
e. He selected three different surfaces (carpet, tile, and concrete) each with three different textures (dry, wet, and icy). His teacher told him that he would need to clarify his experiment before his project would be approved. Which of the following best describes why Anthony's project was rejected? A. Anthony's project has two independent variables. B. Anthony does not have a problem that can be tested. C. The skateboard will not be able to roll along the carpet. D. The friction created by a skateboard cannot be measured.
