Which incendiary weapon did U.S. forces deploy in Vietnam?

• A. White Phosphorus
• B. Agent Orange
• C. Napalm
• D. Cluster bombs

Answer: (C)

The main idea here is recognizing the weapon most famous for starting and sustaining fires across large areas in Vietnam. Napalm fits that description best. It’s a thick, gel-like incendiary mixture that sticks to surfaces—vegetation, buildings, and anything it touches—and burns at incredibly high temperatures for extended periods. When U.S. forces dropped napalm, fires would rapidly engulf target areas, destroying cover, destroying structures, and making it much harder for enemies to maneuver. This combination of adhesive, persistent flame and wide-area destruction made napalm the symbol of incendiary warfare in Vietnam.

White phosphorus also produces fires, but its primary roles were for smoke, illumination, and signaling, with incendiary effects being a secondary use. Agent Orange was a defoliant intended to strip jungle canopy, not to ignite fires. Cluster bombs refer to a delivery method for a variety of payloads and aren’t defined by incendiary effects in the same way napalm is.