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

Which of the following definitions best describes 'Mature spike colour - Estimation'?

A. Observe stem pigmentation as qualitative trait and rate it. Usually recorded during early grain filling stage.
B. Observe the rachilla hair length on the ventral side of the grain and record it.
C. Observe the mature spike colour and rate it.
D. Observe the grain crease width on the ventral side of the grain and record it.

Answer: Observe the mature spike colour and rate it.