Answer:
Technically, It should be Britain, but that isn't an option here.
Step-by-step explanation:
The Slave Trade Act 1807, officially An Act for the Abolition of the Slave Trade, was an Act of the Parliament of the United Kingdom prohibiting the slave trade in the British Empire.
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Hope I Helped, Feel free to ask any questions to clarify :)
Have a great day!
More Love, More Peace, Less Hate.
-Aadi x