Why can’t humans digest all carbohydrates?

Humans are unable to digest cellulose because the appropriate enzymes to breakdown the beta acetal linkages are lacking.

Explanation:

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

the answer would be d : p