Dr. Garza conducts an experiment on memory using participants above the age of 65. Because she cannot include all people above the age of 65, she will selects what is known as a .

sample

Explanation:

sample in research  experiments means when researcher can not include and involve whole population than he or she choose representative sample which represent whole population, and result of experiment can be generalize whole population. Sample must have some characteristics like it must be random and not biased so results get not affected.  

answer; environmental science;