I believe it is l7l+l-2l+l5l+l-8l, or the bottom right answer choice.
The question is asking how many spaces your traveled in total, not solely those you traveled forwards not backwards. Therefore, you just need to count up all of the spaces you moved regardless of whether they were forward(positive) or backwards(negative).
Thus the only possible answer is l7l+l-2l+l5l+l-8l because it is the only choice that allows you to add up all of the numbers regardless of their positivity/negativity.
