exercise6/answer.py: two grading chains, only one validates the range — which is canonical?

[dab00gieman]

answers/exercise6/answer.py contains two grade chains:

mark = 92
if mark >= 90 and mark <= 100: print("A")
elif mark < 90 and mark >= 80: print("B")
elif mark < 80 and mark >= 70: print("C")
else: print("F")

and, further down:

score = 85
if score >= 90 and score <= 100: ...
elif score < 90 and score >= 70: ...
elif score < 70 and score >= 0: ...
else: print("invalid score, score must be between 0 to 100")

The mark chain labels 105 as "F"; the score chain correctly rejects out-of-range values. Which behavior is intended for the curriculum answer — and should the mark chain reuse the score chain's validation?