When teaching a new employee how to operate a piece of machinery the trainer first shows the employee how to do the task while explaining aloud each step. The trainer then shows the new employee the steps again and has the new employee recite the explanation for each step. Then the trainer has the new employee perform each step as they lead them through the tasks verbally. Finally, the trainer has the new employee complete the task on their own and is available for questions. This is an example of _______________. A. formal operations B. conventional thinking C. reasoning D. scaffolding