Productivity is the rate of production of biomass expressed in
1. (ii)
2. (iii)
3. (ii) and (iv)
4. (i) and (iii)
Ans. (c) Productivity is the rate of production of biomass or organic matter by any trophic level per unit area over a time period. It s expressed/measured in terms of weight (e.g. ) or energy (e.g. ).
Page 243, XII NCERT