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

Which of the following classes is one valid superclass of 'vascular leaf anlagen formation stage'?

A. BO.03 late boot stage
B. vascular leaf initiation stage
C. 2.02 main shoot and axillary shoots visible at two nodes stage
D. B enlarged microsporocyte stage

Answer: vascular leaf initiation stage