This interactive line graph visualizes cryptocurrency price and market capitalization trends over time, with dropdown menus to select the metric (price_usd or market_cap) and coin type (bitcoin, ethereum, litecoin, ripple, or bitcoin_cash). The SVG chart animates transitions between datasets using `d3.transition()`, updating the line path, x-axis (time), and y-axis (linear scale) with a duration of 700ms. Data is loaded from `buildings.json` via `d3.json()`, with dates parsed using `d3.timeParse()`, and the y-axis labels are conditionally formatted (e.g., market cap shown in thousands with “k”).