Answer:
D. Buying them.
Step-by-step explanation:
The Trans-Atlantic Slave Trade flourished between 1450 and the end of the 19th century. European traders - Portuguese, Spanish, French, English, Dutch - arrived in their ships and bought local men, women and children. They could also organized campaigns to hunt for slaves in the area, or bought people from local merchants and rulers. The local kings or lords in West Africa were actively involved in selling his own people as slaves for the large profitability of it.