Question

how was william wilberforce, a member of parliament, able to affect the future of slavery in britain?
in 1833, he achieved a ban on the use of enslaved labor in factories.
in 1807, he achieved a ban on british slave trade.
in 1833, he was able to get reduced penalties for runaways.
in 1804, he was able to get an amendment passed abolishing slavery in most northern us states.

Explanation:

William Wilberforce was a key figure in the abolitionist movement. In 1807, the Slave Trade Act was passed in Britain, which abolished the British slave trade. This was a significant achievement in the fight against slavery. The 1833 Slavery Abolition Act (which is related to the end of slavery in British colonies, not just factory labor use as the first option suggests). The third option about reduced penalties for runaways is not a main achievement associated with him in the British context. The fourth option is about the US, not Britain.

Answer:

In 1807, he achieved a ban on British slave trade.