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

Which of the following definitions best describes 'arabidiol synthase activity'?

A. Catalysis of the reaction: (S)-2,3-epoxysqualene = lanosterol. This is a cyclization reaction that forms the sterol nucleus.
B. Catalysis of the reaction: (S)-2,3-epoxysqualene = baruol. Baruol is also known as D:B-Friedo-Baccharan-5,21-dien-3-ol.
C. Catalysis of the reaction: oxidosqualene = marneral.
D. Catalysis of the reaction: oxidosqualene + H2O = arabidiol ((13R,14R,17E)-malabarica-17,21-diene-3beta,14-diol).

Answer: Catalysis of the reaction: oxidosqualene + H2O = arabidiol ((13R,14R,17E)-malabarica-17,21-diene-3beta,14-diol).