Though we don't have the options it's possible to answer this question directly: the correct term is <em>middle passage</em>.
First leg: The triangular trade connected America, Europe, and Africa. From Europe to Africa traveled textiles, rum and manufactured goods that were used to buy slaves.
Second leg: recently bought slaves traveled from Africa to America. This travel is what we call the middle passage.
Third leg: sugar and cotton produced in America by slave labor are taken and sold in Europe.
