Final answer:
The motive for slavery in the sugar colonies was the need for workers on plantations.
Step-by-step explanation:
The motive for slavery, as described in the excerpt, was the need for workers on plantations in the sugar colonies. The excerpt mentions that the White inhabitants of the colonies, who were British subjects, relied on the labor of African slaves to cultivate and harvest sugar and other commodities. The slaves' labor was cheap, enabling the plantation owners to establish costly and extensive works and leading to the affluence of the British masters.
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