Task: Class Relation Understanding (ontology: Sciences/Biology)

Which of the following classes is one valid superclass of 'Aspergone D'?

A. ( -)-1-hydroxybybetaochlamic acid
B. ( Z)-6-benzylidene-3-hydroxymethyl-1,4-dimethyl-3-methylsulfanylpiperazine-2,5-dione
C. butenolide
D. ((18)O)water

Answer: butenolide