Why Are Plants Unlikely to Produce Many Carbohydrates at Night

Multiple Choice

Why are plants unlikely to produce many carbohydrates at night?

A) Selected Calvin cycle enzymes are inactive in the dark because they are hydrogen-bound at night.
B) Calvin cycle enzymes are denatured in the cold temperatures at night.
C) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is oxidized and cannot reduce their disulfide linkages.
D) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is reduced and can break their disulfide linkages.