What system is made up of organs such as the mouth, stomach, and intestines?

The digestive system is the correct answer because it encompasses the various organs that play a vital role in the process of digestion, which includes breaking down food, absorbing nutrients, and expelling waste. The mouth initiates digestion through mechanical and chemical processes, the stomach further breaks down food with acids and enzymes, and the intestines are responsible for absorbing nutrients and water before eliminating indigestible parts. This system is crucial for converting food into energy and nutrients that the body can utilize for growth and maintenance.

The other systems listed, such as the nervous system, respiratory system, and muscular system, serve different essential functions. The nervous system is involved in communication throughout the body, the respiratory system focuses on the exchange of gases (oxygen and carbon dioxide), and the muscular system is responsible for movement and posture. Each of these systems operates independently from the digestive system, highlighting that they do not contain the organs specifically involved in digestion.