Answer: C. A cactus is moved from a sunny windowsill to a dark room.
A cactus is moved from a sunny windowsill to a dark room it represents a disruption in access to the energy source needed by an organism because here, the cactus was previously receiving sunlight from a sunny windowsill as a form of energy which is required to conduct photosynthesis but when it was moved to dark room the access of energy disrupted.