The number of individual organisms of a particular species form a
population
The correct option is A
Explanation -
The incorrect options are B,C and D
Explanation-
B-Group of people with the same species living in a particular area is called a community.
C-Biotic and Abiotic factors are combined to form an ecosystem. it includes living and nonliving factors of the environment.
D- It is the portion of the planet that can sustain life. like aquatic ecosystems, land ecosystems atmospheric ecosystems they combine known as the biosphere.