I think what they are asking is if the polygon was drawn with lines how would you fill it with a color using the two algorithms. I assume scan-line means drawing horizontal lines to fill it and boundary fill is “fill this pixel then fill all it’s neighbors that aren’t filled”.
Sounds like the a really pointless homework question…
Not that it bothers me too much, but i vaguely remember that we had some moderators once … or something. What do they do? Too busy with their own stuff? … just asking.