The correct answer is C. To know whether the students are understanding the lecture or not.
A teacher generally asks questions to his pupils during the lecture to check whether the students are understanding the material being taught. This is important because it allows the teacher to identify any students who may be struggling and need additional help. It also helps to keep the students engaged in the lecture and to ensure that they are retaining the information being presented.
Option A is incorrect because there is no evidence to suggest that asking questions will make students listen more attentively. In fact, some students may find it distracting to be asked questions during a lecture.
Option B is incorrect because there are other ways to identify the most brilliant student in a class, such as giving them extra credit assignments or asking them to lead class discussions.
Option D is incorrect because asking questions is not necessarily a way to help students. In fact, if the questions are too difficult, they may actually confuse or frustrate students.