The core concept is understanding 'common goods', which refers to goods that are non-excludable and non-rivalrous, typically public resources or services. Option B accurately uses 'common goods' in the context of public parks and clean air, which are typically accessible to all and do not diminish when used. Option A is incorrect because customized products are not common goods. Option C misuses the term by describing popular artworks as common goods, which are not public resources. Option D is incorrect as 'common goods' are not usually premium or privately available. Understanding the non-rivalrous and non-excludable nature of common goods is key.