Socialisation is the process by which a newborn gradually becomes a member of a society by absorbing its ways of living. The family is the first agency of this process, and sociologists ask which resource of family life carries the largest part of that teaching.

Customs, rituals, festivals, language habits, food practices and moral codes handed down from one generation to the next form a ready-made store of social learning. A child picks them up without formal instruction, simply by living in the household, and through them acquires the values, roles and expectations that the wider society holds.

The other choices are narrower. Conduct is what the child finally shows, that is the product rather than the resource. Position in the family only decides the privileges a member enjoys. Liking or taste is an individual preference that changes with age and cannot carry a whole culture to the next generation.

Tradition option is correct.