Answer:
a. Bourgeoisie and Proletariat
b. Bourgeoisie owns the means of production and the Proletariat does not.
Step-by-step explanation:
Marx and Engels in the Communist Manifesto have deducted that the whole society is split into the two classes which are Bourgeoisie and Proletariat. The two classes are constantly in conflict throughout history, and these conflicts have always been the driving force of society.
The bourgeoisie is the class that owns the means of production and the capital and therefore are oppressing the other class. The other class, Proletariat, consists of the workers who do not have the means of production but have to rely on selling the labor power. The difference does not lie in the statues, not even in the income, but in the property and the ability to purchase the labor power of others.
The struggle of the working class has become the political struggle as the workers have been rapidly growing. Because of this, Marx believed there has to come to a revolution when the workers shall seize the means of production and redistribute the power.