Answer:
A
Step-by-step explanation:
Radon is an alpha emitter. It emits alpha particles giving off gamma ray. It is a radioactive byproduct of radium-222.
Radon also penetrates the skin. This is because radon is a gas and chemically unreactive with most materials, it moves easily through very small spaces, such as those between particles of soil and rock, to the soil surface
Option B is wrong. It is produced during radioactive decay of radium and not uranium.
Option C is wrong. Radon is not a metallic element.
Option D is wrong also. It is not produced from photochemical smog
Option E is wrong. This is an extension of option B. Uranium is generally used in nuclear plant operations and not radium