C. exocytosis (I have to use 20 characters to respond and "answer it well". Exo means out/outside and exocytosis is an active transport system where a cell uses energy to transport material, like protein or waste, from inside a cell to the outside.)
We first have to understand what a vascular system is. A vascular system consists of the water-carrying tube(xylem) and food-carrying tube(phloem). These 2 tubes are very essential for plants to survive. The xylem transports water to the leaves thru the stem to nourish the leaves so as to make food. The word equation is : Water + Carbon dioxide ----> Glucose + Oxygen. The phloem on the other hand transports the food from the leaves that creates them amd sent them to all parts of the plant. It is often a misconception that food is only sent to the fruits. The plant receives nutrition from the food that is made by the leaves. Overall the vascular system plays a very importamt roles in the survival of the plant.
To put it simple, think of the vascular system of a plant like the circulatory system of a human. Without the circulatory system, the human is unable to receive oxygen for breathing and remove carbon dioxide which is acidic in nature and pose a threat to the human body.
I believe the answer is D.
Photosinthesis is where plants get their sunlight energy
