Task: Class Relation Understanding (ontology: Food_Agriculture/PlantOntology)

Which of the following classes is one valid superclass of 'FL.03 3/4 of flowers open stage'?

A. whole plant flowering stage
B. B enlarged microsporocyte stage
C. IE.03 3/4 of inflorescence emerged from flag leaf sheath stage
D. 2.02 main shoot and axillary shoots visible at two nodes stage

Answer: whole plant flowering stage