Which of the following is true for exocytosis?

A. During exocytosis in skeletal muscle cells, there will be release of calcium ions from intracellular vesicles in the sarcoplasmic reticulum in response to high levels of ryanodine binding to ryanodine receptors in the transverse tubules.

B. During exocytosis in toe motor neurons, there will be release of acetylcholine (ACh) from axonal terminals near toe skeletal muscles in response to an increase in the amount of intracellular calcium in the axonal terminals of these neurons.

C. During exocytosis in collecting duct epithelial cells, there is insertion of AQP4 channels from vesicular membranes into luminal membranes.