The correct answer is 4.
When displaying artworks you need to take into consideration how the elements could possibly damage the art. Artworks are fragile and need to be preserved. Ultraviolet rays from the sun fades paint pigments and the painting will lose it's original colors and vibrancy therefore keeping it out of direct sunlight is best. High temperatures and humidity will damage the painting making it curl or peel or moisture will build up on the surface damaging the paint therefore controlling the temperature and humidity will keep this from happening.
Sounds kinda gay if you ask me, but actually can you provide more context or an actual question ?
