Why Did Slavery and the Slave Trade Continue for Several

Why did slavery and the slave trade continue for several decades after Britain and France abolished its practice in their empires in the 1830s and 1840s?

A) Although slavery was abolished by national legislatures in Europe, few slave owners in the colonies recognized the legitimacy of those acts.
B) Spanish and Portuguese traders continued to trade slaves to Brazil, Cuba, and the United States, where the practice of slavery continued unabated.
C) Slavery continued in outlaw territories that were not under the control of any European government, as traders recaptured freed slaves from maroon communities.
D) Because European governments were so concerned with domestic issues, there was no regulation of the seas or enforcement of the ban on slavery in the affected colonies.