Final answer:
Aerial root system is the best root system that would support plants that grow on other plants to reach light.
Step-by-step explanation:
In environments where light is scarce, some plants grow on other plants to reach light. In such cases, the best root system that would support this mode of life is the aerial root system. Aerial roots are roots that grow above the ground and are adapted to absorb moisture and exchange gases. They are found in plants such as epiphytes, which grow on other plants for support.