Aslave-trade cycle initiated by ship-owners was known as:

slave buying
the atlantic triangle
hiring out
the force act

The correct option is "the Atlantic Triangle"

The Atlantic slave trade, also known as the transatlantic slave trade, refers to the slave trade that took place across the Atlantic Ocean between the 16th and 19th centuries. The vast majority of the slaves involved in Atlantic trade were Africans from the central and western parts of the continent, mostly prisoners of the wars between rival ethnic groups that were sold by African slave traders to European buyers, who transported them to their colonies in North and South America. There, the slaves were forced to work in the plantations of coffee, coconut, tobacco and cotton, in the gold and silver mines, in the rice fields, in the construction industry, in the wood, in the construction of boats and in homes as servants. This occurred in the framework of triangular trade, which was a commercial route that was established in the Atlantic Ocean from the fifteenth to the nineteenth century, so it can be considered a long-standing historical phenomenon.

d is the best answer for this question.

c) troops march forward in close formation against newer, more accurate weapons