Volcanic bombs are . A. volcanic fragments that were ejected while still soft or molten B. explosive bodies of lava with high volatile content C. volcanic fragments that were already solid rock before being ejected during an eruption D. used by geologists to set off small eruptions in volcanoes that are deemed potentially dangerous

C. volcanic fragments that were already solid rock before being ejected during an eruption

Explanation:

A volcanic bomb is a mass of molten rock which is larger than 2.5 inches in diameter, it is formed when a volcano ejects viscous fragments of lava during an eruption like it states up in the answer. They cool into solid fragments before they reach the ground or they turn into solid rock before landing the ground.