The number of individuals an environment can sustain for an indefinite period of time is called its
a. limit of growth.
b. rate of growth.
c. carrying capacity.
d. ideal birth rate.

C. Carry capacity
Carry capacity is defined as the maximum population size of a species that an environment can sustain indefinitely. It is also defined as the environment's maximal load of a species. Factors that impact on the carrying capacity of a species are the availability of food and water, raw materials to build shelter, the environment's ability to process waste products, as well as the species' ability to reproduce. 

Sorry i dont understand the question can you rephase it?