Through which of the following mechanism does glucose mediated insulin release occur?

Glucose enters the beta cells of pancreas GLUT 2 transpoers and is phosphorylated by glucokinase and then metabolized to pyruvate in the cytoplasm. The pyruvate enters the mitochondria and is metabolized to CO2 and H2O the citric acid cycle with the formation of ATP by oxidative phosphorylation. The ATP enters the cytoplasm, where it inhibits ATP-sensitive K+ channels, reducing K+ efflux. This depolarizes the beta cell, and Ca2+ enters the cell voltage-gated Ca2+ channels. The influx of calcium causes exocytosis of insulin-containing secretory granules, resulting in insulin secretion. Ref: Ganong's Review of Medical Physiology, 22nd Edition, Chapter 19, Pages 337-8