The answer is a) and c).
The Communist Manifesto was written by Karl Marx and his colleague Friedrich Engels and published in 1848. This political pamphlet became one of the most influential works in politics.
The Das Kapital was a critical analysis of political economy, written primarily by Karl Max, it consists of 3 volumes, but Max only achieved to publish Volume I (1867), the other two were completed from his notes and published after his death in 1885 and 1894.
d) The tenure of kings and magistrates by the English poet John Milton
b) The prince was written by the Italian Niccolò Machiavelli.