Question

the best way to immobilize an upper arm injury is by—
immobilizing the elbow with a splint.
using a sling and binding it to the chest.
binding it to the other arm.
all of the above

Explanation:

When dealing with an upper - arm injury, immobilization is crucial. Immobilizing the elbow with a splint helps to keep the joint in place. Using a sling and binding it to the chest provides support and restricts movement. Binding it to the other arm also limits motion. Each method contributes to proper immobilization.

Answer:

All of the above