I think its reproductive isolation
The answer is most likely D.
Food is digested, or broken down, so that the nutrients can be extracted for use by the body as it passes through the digestive system. If food wasn't digested you would not have energy required to run vital chemical reactions and eventually resulting death
1. Glucose
2. Calvin cycle ( I might be wrong)
3. Light reaction
Light reaction is the actual food for the plant
Short-term memory holds information for 15 to 25 seconds and stores it according to its meaning rather than just as mere stimulation. However, it is not really true that short-term memory can be retained only for this short amount of time. It has been shown in different studies that it can be held even longer.