Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: Janet learns that Earth is tilted. Due to its tilt, some areas on the surface of Earth experience darkness for an entire day. Which plant process is affected most during this darkness?
photosynthesis
Photosynthesis.