Green Seeker is a sensing system instrument that estimates crop requirement for—

Correct option is B

Option (b): Correct
• GreenSeeker is a Normalized Difference Vegetation Index (NDVI) sensor used in precision agriculture.
• It measures crop canopy reflectance to determine nitrogen requirement in real time.
• It helps optimize fertilizer application and improve nitrogen use efficiency.
Other options are incorrect because GreenSeeker cannot estimate P, K, or micronutrient levels.