I believe the answer is A. horizontal.
Horizontal lines communicate calm feelings, which is definitely something you want to experience if you are going to a vacation resort. You usually go there with your family or on your own to rest from the outside world, so you don't want there to be any chaos.
Perfect fifth because you are going from do to so which is 5 steps apart :) so do to ti would be a perfect seventh since theyre seven steps apart. a perfect octave would be do to do.
"We gain strength, and courage, and confidence by each experience in which we really stop to look fear in the face...we must do that which we think we cannot." - Eleanor Roosevelt
Sing a Ariana Grande song, I am a girl and that's what I like.