Task: Inferred Class Relation Reasoning (ontology: Business_Finance/Occupation_Ontology)

After reasoning, which of the following classes is one valid superclass of 'furnace, Kiln, oven, drier, or Kettle operator or tender (broad)'?

A. material entity
B. physics teacher, postsecondary
C. food cooking machine operator or tender
D. food server, nonrestaurant (broad)

Answer: material entity