Which of the Following Statements About British Involvement in Slavery

Which of the following statements about British involvement in slavery and the slave trade is true?

A) Britain banned the slave trade in 1807 and abolished it in its own colonies in 1833-1834.
B) Britain banned the slave trade and abolished it in its own colonies in 1833-1834.
C) Britain banned the slave trade in 1807 but never abolished it in its own colonies.
D) Britain did not participate in the slave trade but it allowed slavery in its own colonies until 1834.