The correct answers is option B.
B. British parliament outlawed slavery in Britain and it all of its colonies.
It is significant because in that year the members of the Society for the Abolition of the Slave Trade decided to concentrate on a campaign to persuade Parliament to prohibit the trading in slaves, for tactical reasons.
It was not until 1807, when the evils of the trade were generally accepted, that the law was able to pass both Houses.
