The answer is a) and c).
<em>The Communist Manifesto</em> 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 <em>Das Kapital</em> was a critical analysis of political economy, written primarily by Karl Max, it consists of 3 volumes, but Max only achieved to publish <em>Volume I </em>(1867), the other two were completed from his notes and published after his death in 1885 and 1894.
d) <em>The tenure of kings and magistrates</em> by the English poet John Milton
b) <em>The prince was written by the Italian</em> Niccolò Machiavelli.