Which of the following is an example of endocrine signaling?
A. Epinephrine release by motor neurons at the neuromuscular junction and binding to receptors on adjacent skeletal muscle cells
B. Antigen stimulation of T lymphocytes, leading to the stimulation and synthesis of a growth factor that drives their own proliferation
C. Insulin release by β cells in the pancreas, mediating an effect of glucose uptake by muscle cells
D. None of the above