Task: Class Definition Understanding (ontology: Food_Agriculture/Crop_Ontology)

Which of the following definitions best describes 'ZNCONC - Measurement'?

A. Standard method for the total Copper (Cu) content measured in a given volume of petiole extract
B. Measure the width of leaf 3rd lobe
C. Standard method for the total Copper (Cu) content measured in a given volume of root extract
D. Standard method for the total zinc (Zn) concentration measured in a given volume of stem extract

Answer: Standard method for the total zinc (Zn) concentration measured in a given volume of stem extract