To solve this problem, we just need to look for the paths that match each box.
The path from start to finish box is shown by the image below.
As you can observe in the image above, the first connection is on the left of the start box because it matches the segment BD inside the box.
Then, we go to the left again because the second box contains the ray DB.
After, we go through the line BD and choose the path that matches.
We keep using the same logic until we get to the finish box.