b. division between those who own and operate the means of production and those who sell their labor in capitalist societies.
Explanation:
Karl Marx advocates in his book "Das Kapital" (The Capital) that the labors sell the only thing they have, in this case, their strength. This happened, according to Marx, that during the capitalist development, some individuals gain economic power and then began to possess the production means, obligating the ones who didn't have the same to sell the strength in exchange for a sum of money.
