The introduction of ‘The Communist Manifesto’ from 1848 says that ‘a spectre is haunting Europe’. What spectre is it?

Question: The introduction of ‘The Communist Manifesto’ from 1848 says that ‘a spectre is haunting Europe’. What spectre is it?

Choices:

Slavery
Communism
Beetlejuice
War

Correct answer:

Communism