For the growth curve to continue increasing, adaptation to a new habitat is essential. (Option C)
While a variety of organisms in an environment is beneficial, it doesn't guarantee continuous growth. Migration may offer short-term benefits but doesn't ensure sustained growth.
Unlimited resources in an environment are rare and unsustainable. Adaptation, however, allows organisms to adjust to changing conditions, ensuring their survival and reproduction in different habitats.
It's a dynamic process where species evolve traits to thrive in specific environments, contributing to the ongoing upward trajectory of the growth curve over time.
Thus, the right option is Option C.