The stomach wall is muscular and it churns and mixes food. A muscular sphincter prevents escape of food during such churning and mixing.
Bolus (A) is the chewed food swallowed. The formation of bolus is aided by salivary secretions and mastication.
Bile (B) is produced by the liver, aiding in the digestion of lipids. Bile is stored in gall bladder.
Feces (D) is the term used for the (to be) discarded and undigested or unassimilated food. These reside in the colon and rectum before egesting through anus.
Therefore, the options A, B & D are incorrect.
Chyme (C) is the mass of soupy substance that stomach passes on into the duodenum. When the food is thus acted upon, the stomach’s sphincter gives room for passage for the chyme to move on, into the duodenum (for further digestive and assimilatory processes).
Therefore, option (C) is correct.