Social stratification is the arrangement of a society into layers that differ in wealth, occupation, education and prestige. A child is not placed in one of these layers by any act of its own; the position is ascribed at birth through the household into which the child is born.

Everything the layer brings with it reaches the child through that household first. The home decides the standard of living, the dialect and manner of speech, the kind of school chosen, the company allowed, the aspirations encouraged and the restrictions imposed. The child therefore absorbs the attitudes and limits of its stratum from the people who raise it, long before any other influence begins.

The other choices act later and more weakly. A classroom guide meets the child only after schooling starts and treats many children alike. Companions of the same age are themselves usually drawn from a similar layer and so merely repeat the message. The wider collectivity acts through its smaller units, of which the household is the first.

Parents option is correct.