Concept:Remedial teaching is a follow-up step after diagnostic testing. It aims to identify and remove specific learning difficulties of students.Explanation:First, a teacher identifies the exact area where a student faces difficulty. Then, the teacher devises a strategy to remove the causes of those problems. This strategy is called remedial teaching. It uses different methodologies and instructional material based on each student’s individual needs. The goal is not just revision or exam preparation, but to directly address the root of the learner’s weakness. Therefore, remedial teaching is most useful when students have trouble understanding concepts and need targeted help to improve their performance.Answer:D. Addressing the difficulties students are facing in understanding mathematical concepts and improve their performance