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

Which of the following classes is one valid superclass of 'L-homocysteine biosynthetic process'?

A. serine family amino acid biosynthetic process
B. 3',5'-cGMP-stimulated cyclic-nucleotide phosphodiesterase activity
C. 3'-phosphoadenosine 5'-phosphosulfate transport
D. 1,4-alpha-glucan 6-alpha-glucosyltransferase activity

Answer: serine family amino acid biosynthetic process