
THRESHOLD_A = 75.0
THRESHOLD_B = 80.0
THRESHOLD_C = 15.0

# ... existing code ...

# Replace the magic numbers with the named constants:

# Before:
# if score >= 75.0 and score <= 80.0:
#     return "B"
# elif score >= 15.0:
#     return "C"

# After:
if score >= THRESHOLD_A and score <= THRESHOLD_B:
    return "B"
elif score >= THRESHOLD_C:
    return "C"

# And for the module execution block (around line 157):
# Add proper main guard:

if __name__ == "__main__":
    # ... existing main code ...


PASSING_SCORE = 80

# ... existing code ...

# Replace the magic number with the named constant:

# Before:
# if score >= 80:
#     return True

# After:
if score >= PASSING_SCORE:
    return True