Given the Following Pseudocode,what Value of GRADENUM Must Be Input $90 \leq$

Given the following pseudocode,what value of GRADENUM must be input to output a grade of "C"?
Start
Read GRADENUM
CASENTRY GRADENUM
CASE $90 \leq$ GRADENUM $\leq 100$ GRADE $=$ "A'
CASE $80 \leq$ GRADENUM $< 90$ GRADE $=$ 'B'
CASE $70 \leq$ GRADENUM $< 80$ GRADE $=$ "C'
CASE $60 \leq$ GRADENUM $< 70$ GRADE $=$ "D'
CASE other
GRADE $=$ "F"
ENDCASE
Write GRADE
Stop

A) 70 or more
B) 79 or less
C) 80 or less
D) none of the above