Ms.Long took her science class to a buffet to test their digestion system. After eating one serving Melania became really full and want to eat more. She tried rubbing her belly to speed up the digestion process but it did not work. Melania rubbing her belly did not work because ____

A. food digestion is controlled and the muscles in the digestive tract are voluntary muscles.

B. food digestion is not a self-controlled activity and the muscles in the digestive tract are voluntary muscles.

C. food digestion is not a self-controlled activity and the muscles in the digestive tract are involuntary muscles.

D. Melania should have shaken her belly instead of rubbing it.