This example visualizes national median age data for the USA in 2023, displaying the data as a simple text output in the browser. It loads the dataset from a remote CSV file hosted on GitHub using `d3.csv`, then applies the data to the page. The visualization uses D3 version 7, specifically importing the `select` function from the D3 module to manipulate the DOM and update the body text. The code is minimal, with no graphical charts or interactive elements, focusing solely on demonstrating data loading and basic DOM manipulation.