Imagine a glass box that is completely sealed and in that box is a cactus in a small pot. Which statement is most accurate?

AThis is a closed system because light enters through the glass box.
BThis is an open system because light can go through the glass and get into the box.
CThis is a closed system because nothing of substances gets in our out of the box.
DThis is an open system because air is circulating inside the glass box.