Based on the information provided, the individuals in this study are: D. the students.
<h3>What is a study?</h3>
A study can be defined as a strategic process or technique through which a scientist (researcher) observes and measures the effect of a risk factors, diagnostic test, or treatments on a particular population of interest.
<h3>What is a variable?</h3>
In Mathematics, a variable can be defined as the measurable conditions, events, characteristics, individuals, or behaviors that a scientist (researcher) can control or observe when performing a study.
Based on the information provided, the individuals in this study are the students and these include the following subclasses:
Read more on variables here: brainly.com/question/523303
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