Answer:
87-89%
Step-by-step explanation:
According to the Academic grading of the United States, grading system is constituted as it follows:
Letter grade Percentage 
A+ 97–100% 
A 93–96% 
A− 90–92% 
B+ 87–89% 
B 83–86% 
B− 80–82% 
C+ 77–79% 
C 73–76% 
C- 70–72% 
D+ 67–69% 
D 63–66% 
D- 60–62% 
F 0–59%