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

Which of the following classes is one valid superclass of 'sphingomyelin d18:1/23:3'?

A. ((2-bromo-4-methylphenyl){6-[(4-{[(2S)-3-(dimethylamino)-2-hydroxypropyl]oxy}phenyl)amino]pyrimidin-4-yl}amino)acetonitrile
B. sphingomyelin d18:1
C. ((2-bromo-4-methylphenyl){6-[(4-{[(2R)-3-(dimethylamino)-2-hydroxypropyl]oxy}phenyl)amino]pyrimidin-4-yl}amino)acetonitrile
D. ((13)C)carbon dioxide

Answer: sphingomyelin d18:1