What was the middle passage?           a. the route around the southern tip of south america   b. the route through the middle of africa to connect the atlantic and indian oceans   c. the route slave ships took from west africa to the americas   d. the compromise between abolitionist and pro-slavery politicians

The correct option is C.
The middle passage refers to the route which the slave ships that are coming from Africa took to America.
When a slave ship has acquired a full cargo of enslaved Africans, the captain will set out to return to America. This return journey is called middle passage and it normally take the enslave Africans from their homelands across the Atlantic ocean to America.