Answer: b. the maximum number of individuals of a population able to live in an environment.
Step-by-step explanation:
A carrying capacity can be define as the maximum number of individuals of the population of a species which an ecosystem or region can sustain on the basis of availability of resources such as food, water, mates and other resources.
An ecosystem can sustain living beings upto the carrying capacity of the ecosystem. If the population of species exceeds over the carrying capacity then population of the species starts declining.
On the basis of the above explanation, b. the maximum number of individuals of a population able to live in an environment. is the correct option.