Final answer:
The nurse can diagnose low self-esteem from the student's statement of being good at studies but blaming the teacher for poor grades.
Step-by-step explanation:
From the student's statement, the nurse can diagnose low self-esteem. The student's claim of being good at studies but blaming the teacher for poor grades suggests a lack of confidence in their abilities and a tendency to shift blame. It indicates that the student may have a negative perception of themselves and their academic performance.