Ok so i don't really know the rules of Ghost Leg, but i remember playing a videogame that used it as a mechanic, in there you had to take a turn as soon as you encountered an horizontal line, so if lets say you have 2 horizontal lines practically next to each other, you have to take the second one as soon as you come out of the first one
The other one i may be wrong on, is the folding, as i understood you are supposed to fold the paper so that the path would start from an imaginary line drawn from one number to a letter
If i understood things right... and that's a big if, then using this logic my answer would be the line drawn from 5 to E after folding the page