The correct answer is D. Teach.
A teacher asks questions in class to assess student understanding, to promote critical thinking, and to engage students in the learning process. Asking questions can also help to keep students on track and to ensure that they are paying attention.
Option A is incorrect because asking questions is not a way to keep students busy. In fact, asking questions can actually help students to stay focused and engaged in the learning process.
Option B is incorrect because asking questions is not a way to maintain discipline. In fact, asking questions can actually help to create a more positive and productive learning environment.
Option C is incorrect because asking questions is not a way to attract student’s attention. In fact, asking questions can actually help to keep students’ attention focused on the learning material.