Which relation was central to Marx and Engels' criticism of capitalism?

Correct answer: Relation between capitalist and worker

The governing concept is the class relationship created by capitalist production. Marx and Engels distinguished between the bourgeoisie, who owned factories, land, machinery or other means of production, and the proletariat, who owned little productive property and had to sell their labour for wages. Their criticism focused on the unequal power and economic dependence within this relationship, including the claim that owners gained profit from the value created by workers. Hence, option A is correct. The other options describe family, religious, natural or artistic relationships and do not represent the central class contradiction in Marxist criticism of capitalism.