Which of These Is a Function of Intrinsic Factor

Which of these is a function of intrinsic factor?

A) It is secreted by salivary glands,and is necessary for digestion of vitamin B₁₂.
B) It is secreted by parietal cells in the gastric mucosa,and its main function is causing insulin release.
C) It is secreted in the stomach,and its main function is activating pepsinogen into pepsin.
D) It is secreted by the small intestine mucosa,and its main function is initiating the intrinsic electrical activity of the pacemaker cells in the stomach. 
E) It is secreted in the stomach,and a deficiency of it would cause anemia.