Biology · PYQ NEET UG 2025

Which of the following is the unit of productivity of an Ecosystem?

1. A
   \( \text{gm}^{-2} \)
2. B
   \( \text{KCal m}^{-2} \)
3. C
   \( \text{KCal m}^{-3} \)
4. D
   \( (\text{KCal m}^{-2})\text{yr}^{-1} \)