Final answer:
The preferred growth temperature of a microorganism is an example of a phenotypic trait that can be used for identification.
Step-by-step explanation:
The preferred growth temperature of a microorganism is an example of a phenotypic trait that can be used for identification.
Phenotypic traits are observable characteristics of an organism, such as its physical appearance or behavior. In the case of microorganisms, growth temperature preference can vary among different species. For example, some microorganisms prefer warmer temperatures, while others thrive in colder environments. By determining the preferred growth temperature of a microorganism, scientists can distinguish it from closely related microorganisms that have different temperature preferences.
Overall, the answer to this question is B. Phenotypic trait.