Why Are Plants Unlikely to Produce Many Carbohydrates at Night

Why are plants unlikely to produce many carbohydrates at night?

A) Selected Calvin cycle enzymes are inactive in the dark because they denature at night.
B) Selected Calvin cycle enzymes are immobilized at night.
C) Chloroplasts shrink at night.
D) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is oxidized and cannot reduce their disulfide linkages.
E) Selected Calvin cycle enzymes are inactive in the dark because thioredoxin is reduced and can break their disulfide linkages.