B. Customs and Traditions.
You can eliminate A. because different cultures have different religious believes in them and that is not all a culture is bound to. You can eliminate C. because education and training is kind of a "neutral" thing and it is not related to culture hardly at all. You can eliminate D. because there can be many languages within a culture. B. is the best answer because culture are defined by their customs and beliefs and they live by them.
