After 1434, the Following Discovery Accelerated European Contacts with the African

After 1434, the following discovery accelerated European contacts with the African west coast:

A) The adverse currents and prevailing winds along the west coast of Africa that impeded the return journey were overcome by sailing across the Atlantic to the Americas, thence to Europe in what is now known as the triangle trade.
B) The adverse currents and prevailing winds along the west coast of Africa that impeded the return journey were overcome by sailing toward the Atlantic islands such as the Canaries, Madeira, and Azores.
C) The new merchant ships were equipped for both rowing and sailing, using slaves being transported for sale as rowers, keeping them fit as well as expediting the journey.
D) The Portuguese learned new navigation techniques that allowed them to round the southern tip of Africa and sail across the Indian Ocean.