What molecule signals the endothelial cell to produce nitric oxide, and what is the enzymatic reaction?
A. dopamine; L-arginine + 1.5 NADPH + H⁺ + 2O₂ --> dopamine + NO + 1.5 NADP⁺
B. acetylcholine; citrulline + NO + 1.5 NADP⁺ --> L-arginine + 1.5 NADPH + H⁺ + 2O₂
C. acetylcholine; L-arginine + 1.5 NADP⁺ + H⁺ + 2O₂ --> citrulline + NO + 1.5 NADPH
D. citrulline; L-arginine + 1.5 NADP⁺ + H⁺ + 2O₂ --> citrulline + NO + 1.5 NADP⁺