The correct option is C Endoderm
Endoderm is one of the three primary germ layers in the very early embryo. The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems. The entire alimentary canal except part of the mouth, pharynx and the terminal part of the rectum (which are lined by involutions of the ectoderm), the lining cells of all the glands, which open into the digestive tube, including those of the liver and pancreas. Hence, option C is correct.