Why was the piece of equipment in the photo necessary for both sides in World War I?

Question

(1 point)
Responses

to protect the soldiers from diseases
to protect the soldiers from diseases

to protect the soldiers from poisonous gas
to protect the soldiers from poisonous gas

to protect the soldiers from flamethrowers
to protect the soldiers from flamethrowers

to protect the soldiers from machine-gun fire

Answer 1

to protect the soldiers from machine-gun fire.