In what way should a teacher respond to repeated errors made by a student?

The errors that children make during the learning process can be:

Students' errors are important because they - A. are an important tool in classifying students into groups of 'passed' and 'failed'. B. provide a way for teachers to diagnose learning difficulties. C. provide an insight into the child's thinking and help to identify solutions. D. provide space for removing some children from the class.