Which revolutionary packaging innovation was first widely introduced in U.S. military C-rations during World War II?

Throughout military history, combat ration packaging has evolved dramatically to meet the needs of soldiers in the field. From the American Civil War's hardtack boxes to today's sophisticated MREs (Meals, Ready-to-Eat), packaging innovation has been crucial for troop morale and effectiveness. These developments reflect changing military strategies, technological advances, and understanding of nutrition. This poll tests your knowledge of a significant packaging innovation that revolutionized how soldiers accessed their rations during one of history's most significant conflicts.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

The P-38 can opener (also called the 'John Wayne')
Vacuum-sealed plastic pouches
Pull-tab cans
Flameless ration heaters