Most of the Enzymes of the Calvin Cycle Also Function

Multiple Choice

Most of the enzymes of the Calvin cycle also function in other metabolic pathways.This should not be a surprising finding,because

A) metabolic reactions are catalyzed by enzymes that have multiple functions.
B) there is a close relationship between carbohydrate synthesis and metabolic breakdown.
C) the Calvin cycle is nearly ubiquitous in cells,as are metabolic pathways.
D) the Calvin cycle probably evolved at the same time as did glycolysis.