Which of the following is an example of univariate representation?

Univariate representation refers to the visualization of data that involves only one variable to understand its distribution, frequency, or characteristics. In this context, the choice of histogram is correct because a histogram specifically displays the frequency distribution of a single quantitative variable by showing the number of data points that fall within certain ranges (bins). This visual representation helps to effectively summarize and analyze the distribution of values for that one variable.

While scatterplots display the relationship between two quantitative variables, line charts typically depict trends over time and may represent multiple variables. Bar charts can show comparisons between different groups or categories but can also represent multiple variables within their structure. Therefore, these other options are not purely univariate as they typically involve relationships or comparisons between more than one variable. In summary, the histogram is focused on capturing and illustrating the characteristics of one variable, making it a clear example of univariate representation.