Answer:
Sample
Step-by-step explanation:
A sample refers to a small subset of a particular population of study. The sample must be chos n at random in other to ensure that it is representative of the entire population. In the scenario above, all males in the United States aged 18 - 25 years form the population of interest required for the study. However, due to the fact that it is impractical to include all in the study, then a smaller subset is selected form the population, which is referred to as the sample.