Final answer:
Traditional music, folk art, and folk dances are folk customs, while mass-produced goods are not.
Step-by-step explanation:
The folk customs from the choices provided are traditional music, folk art, and folk dances. Traditional music, or folk music, is characterized by being homemade and produced by unschooled musicians using lightweight, homemade, or easily available instruments.
It's tailored to local audiences and influenced by geographic factors and the ethnicity of musicians. Folk art refers to artwork made by culturally homogeneous people without formal training, often for utilitarian purposes and according to regional traditions.
Lastly, folk dances are part of a community's cultural heritage, passed down through generations, and unique to a particular group. Mass-produced goods, by contrast, are not considered folk customs as they are typically the result of industrial production and are not unique to a specific culture or locale.