Answer:
a group of male adults
Step-by-step explanation:
Sample: In psychology, a sample is defined as a group of items, objects, or people taken from a huge or large population for measurement. The sample should be typical to the population, to generalize the findings of a particular study comparative to the entire population.
In the given question, the psychologists chooses the male adult because of the stereotype that male adults consume more alcohols as compare to females. Hence, the gender difference.