The solar radiations from the sun cross through different layers of the atmosphere. While doing so they either get reflected or absorbed across the various elements (clouds and gases) in the atmosphere.
The clouds and gases reflect back one-fourth of the incoming solar radiation. The remaining solar radiation reaches the earth’s surface and heats it.
Later, the earth’s surface re-emits heat in the form of long wave (infrared) radiation which escapes into the space. But some amount of infrared radiation does not escape into space and is held in atmosphere as certain atmospheric gases (e.g., carbon dioxide, methane, etc.) absorb it thus increasing the temperature on earth. This heat trapping phenomenon is called the greenhouse effect and gases responsible for this are called greenhouse gases (carbon dioxide, methane, CFC and nitrous oxide).
Hence, A and B are correct statements and statement C is incorrect.