The correct answer is: C. His teacher congratulated him on his brilliant success in the examination.
The sentence “He was congratulated by his teacher on his brilliant success in the recent examination” is in the passive voice. The passive voice is used when the focus of the sentence is on the action, rather than the person or thing doing the action. In this case, the focus is on the fact that the teacher congratulated the student, not on who did the congratulating.
The active voice version of the sentence would be: “His teacher congratulated him on his brilliant success in the recent examination.” In this version, the focus is on the teacher, who is the person doing the action.
The other options are incorrect because they do not reflect the meaning of the original sentence. Option A is incorrect because it says that the student congratulated the teacher. Option B is incorrect because it says that the teacher congratulated the student for his success, but it does not specify what the student succeeded at. Option D is incorrect because it does not include any information about the student’s success.