Legend 1 — Sectional Aeronautical Chart · FAA-CT-8080-2H, p. 1-1
On a sectional chart, which line style marks the boundary of Class B airspace?
Why: FAA-CT-8080-2H Legend 1's Airport Traffic Service and Airspace Information panel shows Class B airspace as a solid blue line, distinct from Class C's solid magenta line and Class D's dashed blue line.
That is the symbol for Class C airspace, not Class B — a common mix-up between the two solid-line airspace classes.
That is the symbol for Class D airspace; Class D uses a dashed blue line, while Class B uses a solid blue line.