This interactive line chart displays energy consumption data across multiple building sites, allowing users to switch between locations via a dropdown menu. The visualization employs an SVG-rendered multi-series plot with a smooth animated transition when a new site is selected. The code uses `d3.csv` for data ingestion, `d3.scaleLinear` for axes, `d3.line` for plotting, and `d3.transition` to animate changes. A color scale assigns distinct hues to each site. The chart reveals periodic patterns in usage, with site 7 showing notable gaps where zero consumption was recorded.