Which body system adds oxygen to the blood? Respiratory System Digestive System D Endocrine System Muscular System

## Step 1<br />The question asks which body system adds oxygen to the blood. The options provided are the Respiratory System, Digestive System, Endocrine System, and Muscular System.<br /><br />## Step 2<br />The Respiratory System is responsible for the exchange of gases, including oxygen and carbon dioxide, between the body and the environment. This process occurs in the lungs, where oxygen is absorbed into the bloodstream and carbon dioxide is expelled.<br /><br />## Step 3<br />The Digestive System is responsible for breaking down food into nutrients, which the body can then use for energy, growth, and cell repair. It does not add oxygen to the blood.<br /><br />## Step 4<br />The Endocrine System produces hormones that regulate various bodily functions, but it does not add oxygen to the blood.<br /><br />## Step 5<br />The Muscular System is responsible for movement and maintaining posture, but it does not add oxygen to the blood.