Answer: C) Radioactive particles ionize argon gas in a tube and the resulting electric current is amplified and heard as a clicking sound.
Step-by-step explanation:
Heighten counters contain a sealed tube or chamber that is filled with gas (usually helium or argon) and they have an information display. radiation enters the tube and once it collided with the gas, an electron is pushed away from the gas atom and creates an ion pair and a speaker makes a clicking sound everytime an ion pair is created.