Which statement best summarizes what karl marx predicted regarding the differences in social classes within a society

Karl Marx believed that the economy determined the nature of society. He predicted that society would be reduced down to two social classes: bourgeoisie and proletariat. The bourgeoisie is the class that owns the means of production, in other words, they would be the rulers of the society. The proletariat is the class that labors with out owning the means of production, in other words, the class that is ruled.

option a is correct i.e.

only sodium ions can pass through the membrane.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

They create genetic variations