Answer:
Allow carbon to enter an ecosystem through photosynthesis
Step-by-step explanation:
Though plants are known to sustain life through the process of photosynthesis. In this process plants simply takes in carbon dioxide and releases oxygen.
However, this is a type of process is considered to be active during the day, while at night plants absorb oxygen and release carbon dioxide
Hence, Plants play a crucial role in the carbon cycle because they "Allow carbon to enter an ecosystem through photosynthesis."