it is important that you maintain a healthy weight both for your overall health and so that your respiratory system can

a allow for smaller amounts of air to enter your lungs
b pump blood more forcefully from the heart
c keep capillaries constricted
d deliver oxygen more adequately

d. deliver oxygen more adequately

Maintaining a healthy weight ensures that your respiratory system can function properly and deliver oxygen effectively to all parts of your body. Being at a healthy weight also reduces the strain on your heart and blood vessels, allowing for better circulation and overall cardiovascular health.