i. (kcal m–3) yr–1

ii. g–2 yr–1

iii. g–1 yr–1

iv. (kcal m–2) yr–1

(a)ii, (b) iii, (c) ii and iv, (d) i and iii

Correct option – ( c )

Explanation – the rate of synthesis of energy containing organic matter or biomass by any trophic level per unit area in unit time is known as productivity . It is expressed as – g–2 yr–1 and (kcal m–2) yr–1

Hence correct answer is – g–2 yr–1 and (kcal m–2) yr–1