The map below shows major Afro-Eurasian trade circuits active c. 1200–1450. Based on the routes shown, which circuit connected West Africa to the Mediterranean world using an entirely overland route?

The map marks the Timbuktu–Cairo link with a dashed line and labels it "Trans-Saharan (dashed)" — the only circuit on the map that runs entirely over land, crossing the Sahara to connect West African gold- and salt-producing regions to Mediterranean and Middle Eastern markets. The Silk Roads segment between Constantinople and Baghdad is also overland, but it does not connect West Africa. The Indian Ocean legs (Calicut–Malacca, Quanzhou–Hormuz) are maritime routes, shown as solid lines running through coastal port cities rather than across a desert interior.