Final answer:
The stomach does not play a role in masticating food; this process occurs in the mouth where teeth chew the food, saliva from the salivary glands moistens it, and the tongue moves it to the pharynx. Hence, option (d) is correct.
Step-by-step explanation:
Among the options given, the one that does not play a role in masticating food is d) Stomach. The process of mastication involves the breakdown of food in the mouth before it is swallowed. The teeth and jaw are responsible for mechanically chewing the food, while the salivary glands produce saliva that moistens the food and begins the chemical digestion of starches and fats. The tongue helps to move the chewed food, forming a bolus and pushes it toward the pharynx.
It is from here that peristalsis begins, which helps in moving the food from the pharynx to the esophagus, and eventually to the stomach for further digestion. However, the stomach itself is not involved in the mastication process, as mastication occurs in the oral cavity only.