It's A. All you have to remember here are your rules of translations. If there is side to side movement within a parabola it will be indicated within a set of parenthesis with the x coordinate. If there is no set of parenthesis with the x there is no side to side movement. The quantity

tells us that the vertex has moved left 3 units.
18 = (240/100) x what;
what = 18 x (100/240);
what = 1800/240;
what = 7.5;
Before:It's too short. Write at least 20 characters to explain it well.
After:It's too short. Write at least 20 characters to explain it well.
By definition we have the following equation:
t = d / v
Where,
t: time
d: distance
v: speed
For this case we have:
d / 30 + d / 4 = 17
Rewriting we have:
2d + 15d = 17 (60)
17d = 17 (60)
d = 60 mi
Then, the walking time is
t = d / v
t = 60/4
t = 15 hours
Answer:
She walked
t = 15 hours