Final answer:
A variable is a characteristic that takes on different values and is used in quantitative research.
Step-by-step explanation:
A characteristic or quality that takes on different values and varies from one person to the next is called a variable. Variables are used almost exclusively in quantitative research. In statistics, variables are notated by capital letters such as X and Y. They can describe values like weight in pounds or favorite subject in school. Numerical variables, such as weight in pounds and time in hours, take on values with equal units. Categorical variables, like a person's party affiliation, place individuals or things into categories. The correct answer is C) Variables.