Which of the following variables is quantitative?

A quantitative variable is one that can be measured and expressed numerically, allowing for mathematical operations such as addition, subtraction, and statistical analysis. The square footage of a residential home is indeed a quantitative variable because it represents a measurable quantity that can vary in numerical form—such as 1,500 square feet, 2,000 square feet, etc. This variable provides concrete data that can be used for comparisons, calculations, and data analysis.

In contrast, the other options describe qualitative variables. A people's favorite sport and political party affiliation are categorical variables that classify data without providing numerical values. They cannot be quantified in a meaningful numerical way, thus lacking any inherent metric for measurement. Similarly, the type of customer complaint is also categorical, as it identifies the nature of grievances rather than quantifying an attribute or measurement.