In the choices above, the correct letter of the question is letter a, scintillation counter. It is because it uses a phosphor-coated surface in order to use its function in detecting radiation. Its component could produce bright flashes where it will be sufficient in detecting the radiation.
<span>19.992*0.9048+20.993*0.0027+21.991+0.0925 = </span><span> 20.1797 amu (C)</span>
