The correct answer is aquella, because we would use the word if there was a difference in the distance. Like if you were in the right corner of a room, and the guitar was at the left corner of the room. And another reason is because aquella is feminine and in spanish, guitar is feminine.
Be more specific.
If she buys a bottle of water to cost 1.85, she gets the bottle of water and loses the 1.85 she used to have.
Este verano, nosotros vamos a ir de vacaciones a Peru.
I couldn’t quite understand it, but I hope this helps!