Question

the japanese utilized ______ to sink u.s. ships.
grenades
kamikazes
submarines

Explanation:

During World War II, the Japanese used kamikazes (pilots who conducted suicide attacks by crashing their planes into U.S. ships) to sink U.S. ships. Grenades are handheld explosives not suitable for sinking ships from a distance/air, and while Japan used submarines, the kamikaze tactic was more prominently used for attacking ships in this context.

Answer:

kamikazes